diff --git a/actions/sprint-draft.ts b/actions/sprint-draft.ts
index ddbe395..37beb54 100644
--- a/actions/sprint-draft.ts
+++ b/actions/sprint-draft.ts
@@ -26,8 +26,8 @@ const StoryOverridesSchema = z.object({
 
 const DraftSchema = z.object({
   goal: z.string().min(1),
-  startAt: z.string().datetime().optional(),
-  endAt: z.string().datetime().optional(),
+  startAt: z.string().date().optional(),
+  endAt: z.string().date().optional(),
   pbiIntent: z.record(z.string(), z.enum(['all', 'none'])).default({}),
   storyOverrides: z.record(z.string(), StoryOverridesSchema).default({}),
 }).strict()
diff --git a/app/(app)/products/[id]/page.tsx b/app/(app)/products/[id]/page.tsx
index 386fe56..8ea05fe 100644
--- a/app/(app)/products/[id]/page.tsx
+++ b/app/(app)/products/[id]/page.tsx
@@ -15,7 +15,8 @@ import { UrlTaskSync } from '@/components/backlog/url-task-sync'
 import { TaskDialog } from '@/app/_components/tasks/task-dialog'
 import { EditTaskLoader } from '@/app/_components/tasks/edit-task-loader'
 import { TaskDialogSkeleton } from '@/app/_components/tasks/task-dialog-skeleton'
-import { StartSprintButton } from '@/components/sprint/start-sprint-button'
+import { NewSprintTrigger } from '@/components/backlog/new-sprint-trigger'
+import { SprintDraftBanner } from '@/components/backlog/sprint-draft-banner'
 import { ActivateProductButton } from '@/components/shared/activate-product-button'
 import { EditProductButton } from '@/components/products/edit-product-button'
 import { SprintSwitcher } from '@/components/shared/sprint-switcher'
@@ -118,13 +119,12 @@ export default async function ProductBacklogPage({ params, searchParams }: Props
           {!isActiveProduct && (
             <ActivateProductButton productId={id} isDemo={isDemo} redirectTo={`/products/${id}`} />
           )}
-          {hasOpenSprint ? (
+          {hasOpenSprint && (
             <Link href={`/products/${id}/sprint`} className="text-xs text-primary hover:underline font-medium">
               Sprint actief →
             </Link>
-          ) : (
-            !isDemo && <StartSprintButton productId={id} />
           )}
+          {!isDemo && <NewSprintTrigger productId={id} isDemo={isDemo} />}
           {!isDemo && product.user_id === session.userId && (
             <EditProductButton
               product={{
@@ -147,6 +147,9 @@ export default async function ProductBacklogPage({ params, searchParams }: Props
         </div>
       </div>
 
+      {/* Sprint definition banner (state A′) */}
+      <SprintDraftBanner productId={id} />
+
       {/* Split pane */}
       <div className="flex-1 overflow-hidden">
         <BacklogHydrationWrapper
diff --git a/components/backlog/new-sprint-metadata-dialog.tsx b/components/backlog/new-sprint-metadata-dialog.tsx
new file mode 100644
index 0000000..cccf9a9
--- /dev/null
+++ b/components/backlog/new-sprint-metadata-dialog.tsx
@@ -0,0 +1,203 @@
+'use client'
+
+import { useRef, useState, useTransition } from 'react'
+import { toast } from 'sonner'
+import { Button } from '@/components/ui/button'
+import { Textarea } from '@/components/ui/textarea'
+import { Dialog, DialogContent, DialogTitle } from '@/components/ui/dialog'
+import {
+  useDirtyCloseGuard,
+  DirtyCloseGuardDialog,
+} from '@/components/shared/use-dirty-close-guard'
+import { useDialogSubmitShortcut } from '@/components/shared/use-dialog-submit-shortcut'
+import {
+  entityDialogContentClasses,
+  entityDialogFooterClasses,
+  entityDialogHeaderClasses,
+} from '@/components/shared/entity-dialog-layout'
+import { useUserSettingsStore } from '@/stores/user-settings/store'
+import { debugProps } from '@/lib/debug'
+
+interface NewSprintMetadataDialogProps {
+  open: boolean
+  productId: string
+  onOpenChange: (open: boolean) => void
+}
+
+function todayLocalDate(): string {
+  return new Date().toLocaleDateString('en-CA')
+}
+
+function plusWeeks(weeks: number): string {
+  const d = new Date()
+  d.setDate(d.getDate() + weeks * 7)
+  return d.toLocaleDateString('en-CA')
+}
+
+export function NewSprintMetadataDialog({
+  open,
+  productId,
+  onOpenChange,
+}: NewSprintMetadataDialogProps) {
+  const [sprintGoal, setSprintGoal] = useState('')
+  const [startDate, setStartDate] = useState(todayLocalDate())
+  const [endDate, setEndDate] = useState(plusWeeks(2))
+  const [error, setError] = useState<string | null>(null)
+  const [dirty, setDirty] = useState(false)
+  const [isPending, startTransition] = useTransition()
+  const formRef = useRef<HTMLFormElement>(null)
+  const setPendingSprintDraft = useUserSettingsStore(
+    (s) => s.setPendingSprintDraft,
+  )
+
+  function reset() {
+    setSprintGoal('')
+    setStartDate(todayLocalDate())
+    setEndDate(plusWeeks(2))
+    setError(null)
+    setDirty(false)
+  }
+
+  const closeGuard = useDirtyCloseGuard(dirty, () => {
+    onOpenChange(false)
+    reset()
+  })
+
+  function handleSubmit(e: React.FormEvent) {
+    e.preventDefault()
+    const goal = sprintGoal.trim()
+    if (!goal) return
+    setError(null)
+    startTransition(async () => {
+      try {
+        await setPendingSprintDraft(productId, {
+          goal,
+          startAt: startDate || undefined,
+          endAt: endDate || undefined,
+          pbiIntent: {},
+          storyOverrides: {},
+        })
+        reset()
+        onOpenChange(false)
+      } catch (err) {
+        const message =
+          err instanceof Error ? err.message : 'Onbekende fout bij opslaan'
+        setError(message)
+        toast.error(message)
+      }
+    })
+  }
+
+  const handleKeyDown = useDialogSubmitShortcut(() =>
+    formRef.current?.requestSubmit(),
+  )
+
+  return (
+    <>
+      <Dialog
+        open={open}
+        onOpenChange={(o) => {
+          if (!o) closeGuard.attemptClose()
+          else onOpenChange(o)
+        }}
+      >
+        <DialogContent
+          showCloseButton={false}
+          onKeyDown={handleKeyDown}
+          className={entityDialogContentClasses}
+          {...debugProps(
+            'new-sprint-metadata-dialog',
+            'NewSprintMetadataDialog',
+            'components/backlog/new-sprint-metadata-dialog.tsx',
+          )}
+        >
+          <div className={entityDialogHeaderClasses}>
+            <DialogTitle className="text-xl font-semibold">
+              Nieuwe sprint
+            </DialogTitle>
+            <p className="text-xs text-muted-foreground mt-1">
+              Geef het sprint-doel en periode op. Je selecteert daarna PBI&apos;s
+              en stories via vinkjes in de backlog.
+            </p>
+          </div>
+
+          <form
+            ref={formRef}
+            id="new-sprint-metadata-form"
+            onSubmit={handleSubmit}
+            onChange={() => setDirty(true)}
+            className="flex-1 overflow-y-auto px-6 py-6 space-y-6"
+          >
+            <div className="space-y-1.5">
+              <label className="text-sm font-medium text-foreground">
+                Sprint Goal <span className="text-error">*</span>
+              </label>
+              <Textarea
+                value={sprintGoal}
+                onChange={(e) => setSprintGoal(e.target.value)}
+                required
+                rows={3}
+                placeholder="Wat wil je aan het einde van deze Sprint bereikt hebben?"
+                autoFocus
+              />
+            </div>
+
+            <div className="grid grid-cols-2 gap-3">
+              <div className="space-y-1.5">
+                <label className="text-sm font-medium text-foreground">
+                  Startdatum
+                </label>
+                <input
+                  type="date"
+                  value={startDate}
+                  onChange={(e) => setStartDate(e.target.value)}
+                  className="w-full rounded-md border border-border bg-surface-container px-3 py-2 text-sm focus:outline-none focus:ring-1 focus:ring-primary"
+                />
+              </div>
+              <div className="space-y-1.5">
+                <label className="text-sm font-medium text-foreground">
+                  Einddatum
+                </label>
+                <input
+                  type="date"
+                  value={endDate}
+                  onChange={(e) => setEndDate(e.target.value)}
+                  className="w-full rounded-md border border-border bg-surface-container px-3 py-2 text-sm focus:outline-none focus:ring-1 focus:ring-primary"
+                />
+              </div>
+            </div>
+
+            {error && (
+              <div className="bg-error-container text-error-container-foreground rounded-lg px-3 py-2 text-sm border-l-4 border-error">
+                {error}
+              </div>
+            )}
+          </form>
+
+          <div className={entityDialogFooterClasses}>
+            <div className="flex justify-end gap-2">
+              <Button
+                type="button"
+                variant="ghost"
+                onClick={closeGuard.attemptClose}
+                disabled={isPending}
+              >
+                Annuleren
+              </Button>
+              <Button
+                type="submit"
+                form="new-sprint-metadata-form"
+                disabled={isPending || !sprintGoal.trim()}
+                data-debug-id="new-sprint-metadata-dialog__submit"
+              >
+                {isPending ? 'Opslaan…' : 'Verder'}
+              </Button>
+            </div>
+          </div>
+        </DialogContent>
+      </Dialog>
+
+      <DirtyCloseGuardDialog guard={closeGuard} />
+    </>
+  )
+}
diff --git a/components/backlog/new-sprint-trigger.tsx b/components/backlog/new-sprint-trigger.tsx
new file mode 100644
index 0000000..ccf07d7
--- /dev/null
+++ b/components/backlog/new-sprint-trigger.tsx
@@ -0,0 +1,46 @@
+'use client'
+
+import { useState } from 'react'
+import { Button } from '@/components/ui/button'
+import { DemoTooltip } from '@/components/shared/demo-tooltip'
+import { useUserSettingsStore } from '@/stores/user-settings/store'
+import { NewSprintMetadataDialog } from './new-sprint-metadata-dialog'
+
+interface NewSprintTriggerProps {
+  productId: string
+  isDemo: boolean
+}
+
+/**
+ * PBI-79 / ST-1337: trigger-knop voor de nieuwe sprint-flow.
+ * Verbergt zichzelf wanneer er al een pendingSprintDraft loopt — dan
+ * staat de SprintDefinitionBanner zelf de afronding te regelen.
+ */
+export function NewSprintTrigger({ productId, isDemo }: NewSprintTriggerProps) {
+  const [open, setOpen] = useState(false)
+  const hasDraft = useUserSettingsStore(
+    (s) => !!s.entities.settings.workflow?.pendingSprintDraft?.[productId],
+  )
+
+  if (hasDraft) return null
+
+  return (
+    <>
+      <DemoTooltip show={isDemo}>
+        <Button
+          size="sm"
+          onClick={() => setOpen(true)}
+          disabled={isDemo}
+          data-debug-id="new-sprint-trigger"
+        >
+          Nieuwe sprint
+        </Button>
+      </DemoTooltip>
+      <NewSprintMetadataDialog
+        open={open}
+        productId={productId}
+        onOpenChange={setOpen}
+      />
+    </>
+  )
+}
diff --git a/components/backlog/pbi-list.tsx b/components/backlog/pbi-list.tsx
index 48b007e..3752d95 100644
--- a/components/backlog/pbi-list.tsx
+++ b/components/backlog/pbi-list.tsx
@@ -21,7 +21,7 @@ import {
 } from '@dnd-kit/sortable'
 import { CSS } from '@dnd-kit/utilities'
 import { toast } from 'sonner'
-import { CheckSquare, Square } from 'lucide-react'
+import { CheckSquare, MinusSquare, Square } from 'lucide-react'
 import { Button } from '@/components/ui/button'
 import { Badge } from '@/components/ui/badge'
 import {
@@ -32,7 +32,11 @@ import {
 import { useShallow } from 'zustand/react/shallow'
 import { useUserSettingsStore } from '@/stores/user-settings/store'
 import { useProductWorkspaceStore } from '@/stores/product-workspace/store'
-import { selectVisiblePbis } from '@/stores/product-workspace/selectors'
+import {
+  selectPbiTriState,
+  selectVisiblePbis,
+  type PbiTriState,
+} from '@/stores/product-workspace/selectors'
 import type { BacklogPbi as WorkspacePbi } from '@/stores/product-workspace/types'
 import { deletePbiAction } from '@/actions/pbis'
 import { reorderPbisAction, updatePbiPriorityAction } from '@/actions/stories'
@@ -41,7 +45,6 @@ import { debugProps } from '@/lib/debug'
 import { PbiDialog, type PbiDialogState } from './pbi-dialog'
 import { BacklogCard } from './backlog-card'
 import { EmptyPanel } from './empty-panel'
-import { NewSprintDialog } from '@/components/sprint/new-sprint-dialog'
 import { DemoTooltip } from '@/components/shared/demo-tooltip'
 import { PRIORITY_COLORS } from '@/components/shared/priority-select'
 import { PBI_STATUS_LABELS, PBI_STATUS_COLORS } from '@/components/shared/pbi-status-select'
@@ -80,12 +83,20 @@ interface PbiListProps {
 }
 
 // --- Sortable PBI row ---
+function TriStateIcon({ state }: { state: PbiTriState }) {
+  if (state === 'full')
+    return <CheckSquare size={18} className="text-primary" />
+  if (state === 'partial')
+    return <MinusSquare size={18} className="text-primary" />
+  return <Square size={18} />
+}
+
 function SortablePbiRow({
   pbi,
   isSelected,
   isDemo,
   selectionMode,
-  isChecked,
+  triState,
   onSelect,
   onToggleCheck,
   onEdit,
@@ -95,7 +106,7 @@ function SortablePbiRow({
   isSelected: boolean
   isDemo: boolean
   selectionMode: boolean
-  isChecked: boolean
+  triState: PbiTriState
   onSelect: () => void
   onToggleCheck: () => void
   onEdit: () => void
@@ -112,6 +123,7 @@ function SortablePbiRow({
   }
 
   if (selectionMode) {
+    const isChecked = triState !== 'empty'
     return (
       <BacklogCard
         ref={setNodeRef}
@@ -135,7 +147,7 @@ function SortablePbiRow({
             className="inline-flex items-center justify-center min-h-7 min-w-7 text-muted-foreground"
             aria-hidden="true"
           >
-            {isChecked ? <CheckSquare size={18} className="text-primary" /> : <Square size={18} />}
+            <TriStateIcon state={triState} />
           </div>
         }
       />
@@ -216,23 +228,21 @@ export function PbiList({ productId, isDemo }: PbiListProps) {
   const [filterPopoverOpen, setFilterPopoverOpen] = useState(false)
   const [dialogState, setDialogState] = useState<PbiDialogState | null>(null)
   const [activeDragId, setActiveDragId] = useState<string | null>(null)
-  const [selectionMode, setSelectionMode] = useState(false)
-  const [selectedIds, setSelectedIds] = useState<Set<string>>(new Set())
-  const [newSprintOpen, setNewSprintOpen] = useState(false)
   const [, startTransition] = useTransition()
 
-  function exitSelection() {
-    setSelectionMode(false)
-    setSelectedIds(new Set())
-  }
+  // PBI-79 / ST-1337: selectionMode is afgeleid van pendingSprintDraft.
+  // Wanneer er een draft voor dit product bestaat zit de pagina in state A′
+  // en tonen we tri-state-vinkjes; klik = upsertPbiIntent.
+  const hasDraft = useUserSettingsStore(
+    (s) => !!s.entities.settings.workflow?.pendingSprintDraft?.[productId],
+  )
+  const upsertPbiIntent = useUserSettingsStore((s) => s.upsertPbiIntent)
+  const selectionMode = hasDraft
 
-  function toggleCheck(id: string) {
-    setSelectedIds(prev => {
-      const next = new Set(prev)
-      if (next.has(id)) next.delete(id)
-      else next.add(id)
-      return next
-    })
+  function togglePbiInDraft(id: string, currentState: PbiTriState) {
+    // empty → all; partial → all; full → none.
+    const nextIntent = currentState === 'full' ? 'none' : 'all'
+    void upsertPbiIntent(productId, id, nextIntent)
   }
 
   // pbis komen al gesorteerd binnen via selectVisiblePbis (priority + sort_order).
@@ -398,21 +408,6 @@ export function PbiList({ productId, isDemo }: PbiListProps) {
             setSortDir('asc')
           }}
         />
-        <DemoTooltip show={isDemo}>
-          <Button
-            size="sm"
-            variant={selectionMode ? 'default' : 'outline'}
-            className="h-7 text-xs"
-            disabled={isDemo}
-            onClick={() => {
-              if (isDemo) return
-              if (selectionMode) exitSelection()
-              else setSelectionMode(true)
-            }}
-          >
-            {selectionMode ? 'Selecteren stoppen' : "Selecteer PBI's"}
-          </Button>
-        </DemoTooltip>
         <DemoTooltip show={isDemo}>
           <Button
             size="sm"
@@ -445,15 +440,15 @@ export function PbiList({ productId, isDemo }: PbiListProps) {
             >
               <div className="p-3 flex flex-col gap-2" {...debugProps('pbi-list__items')}>
                 {filtered.map(pbi => (
-                  <SortablePbiRow
+                  <SortablePbiRowWithTriState
                     key={pbi.id}
                     pbi={pbi}
                     isSelected={selectedPbiId === pbi.id}
                     isDemo={isDemo}
                     selectionMode={selectionMode}
-                    isChecked={selectedIds.has(pbi.id)}
+                    productId={productId}
                     onSelect={() => useProductWorkspaceStore.getState().setActivePbi(pbi.id)}
-                    onToggleCheck={() => toggleCheck(pbi.id)}
+                    onToggle={togglePbiInDraft}
                     onEdit={() => setDialogState({ mode: 'edit', productId, pbi })}
                     onDelete={() => handleDelete(pbi.id)}
                   />
@@ -474,53 +469,72 @@ export function PbiList({ productId, isDemo }: PbiListProps) {
         )}
       </div>
 
-      {selectionMode && (
-        <div className="border-t border-border bg-surface-container px-4 py-2 flex items-center justify-between gap-2 shrink-0">
-          <span className="text-sm text-foreground">
-            {selectedIds.size} geselecteerd
-          </span>
-          <div className="flex items-center gap-2">
-            <Button
-              size="sm"
-              variant="ghost"
-              className="h-7 text-xs"
-              onClick={exitSelection}
-            >
-              Annuleer
-            </Button>
-            <Button
-              size="sm"
-              className="h-7 text-xs"
-              disabled={selectedIds.size === 0}
-              onClick={() => setNewSprintOpen(true)}
-            >
-              Nieuwe sprint
-            </Button>
-          </div>
-        </div>
-      )}
-
       <PbiDialog
         state={dialogState}
         onClose={() => setDialogState(null)}
         isDemo={isDemo}
       />
-
-      <NewSprintDialog
-        open={newSprintOpen}
-        productId={productId}
-        pbiIds={Array.from(selectedIds)}
-        onOpenChange={(open) => {
-          setNewSprintOpen(open)
-          if (!open) {
-            // Sluit selectie bij geslaagde aanmaak; bij annuleren laat de selectie staan
-          }
-        }}
-        onCreated={() => {
-          setNewSprintOpen(false)
-          exitSelection()
-        }}
-      />
     </div>
   )
 }
+
+// PBI-79 / ST-1337: wrapper rond SortablePbiRow die zijn tri-state uit de
+// workspace-store leest. Subscribed per PBI zodat alleen de relevante rij
+// re-rendert bij pbiIntent/storyOverrides-mutaties.
+function SortablePbiRowWithTriState({
+  pbi,
+  isSelected,
+  isDemo,
+  selectionMode,
+  productId,
+  onSelect,
+  onToggle,
+  onEdit,
+  onDelete,
+}: {
+  pbi: Pbi
+  isSelected: boolean
+  isDemo: boolean
+  selectionMode: boolean
+  productId: string
+  onSelect: () => void
+  onToggle: (id: string, currentState: PbiTriState) => void
+  onEdit: () => void
+  onDelete: () => void
+}) {
+  // Tri-state uit pendingSprintDraft (state A′) of pbiSummary (state B).
+  // Wanneer geen draft: leid af van pbiSummary; wanneer wel: uit pbiIntent.
+  const triState = useUserSettingsStore((s) => {
+    const draft = s.entities.settings.workflow?.pendingSprintDraft?.[productId]
+    if (draft) {
+      const intent = draft.pbiIntent[pbi.id] ?? 'none'
+      const override = draft.storyOverrides[pbi.id]
+      if (intent === 'all') {
+        if (override?.remove.length) return 'partial'
+        return 'full'
+      }
+      if (override?.add.length) return 'partial'
+      return 'empty'
+    }
+    return null
+  })
+  const summaryTriState = useProductWorkspaceStore((s) =>
+    selectPbiTriState(s, pbi.id),
+  )
+  const effectiveTriState: PbiTriState =
+    triState ?? (selectionMode ? summaryTriState : 'empty')
+
+  return (
+    <SortablePbiRow
+      pbi={pbi}
+      isSelected={isSelected}
+      isDemo={isDemo}
+      selectionMode={selectionMode}
+      triState={effectiveTriState}
+      onSelect={onSelect}
+      onToggleCheck={() => onToggle(pbi.id, effectiveTriState)}
+      onEdit={onEdit}
+      onDelete={onDelete}
+    />
+  )
+}
diff --git a/components/backlog/sprint-definition-banner.tsx b/components/backlog/sprint-definition-banner.tsx
new file mode 100644
index 0000000..e013881
--- /dev/null
+++ b/components/backlog/sprint-definition-banner.tsx
@@ -0,0 +1,176 @@
+'use client'
+
+import { useMemo, useState, useTransition } from 'react'
+import { toast } from 'sonner'
+import { Button } from '@/components/ui/button'
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+} from '@/components/ui/alert-dialog'
+import { useUserSettingsStore } from '@/stores/user-settings/store'
+import { useProductWorkspaceStore } from '@/stores/product-workspace/store'
+import type { PendingSprintDraft } from '@/lib/user-settings'
+import { debugProps } from '@/lib/debug'
+
+interface SprintDefinitionBannerProps {
+  productId: string
+  draft: PendingSprintDraft
+}
+
+type DraftCounts = {
+  pbiCount: number
+  storyCount: number
+  hasUnknownTotal: boolean
+}
+
+function computeCounts(
+  draft: PendingSprintDraft,
+  pbiSummary: Record<
+    string,
+    { totalStoryCount: number; inActiveSprintStoryCount: number }
+  >,
+): DraftCounts {
+  let pbiCount = 0
+  let storyCount = 0
+  let hasUnknownTotal = false
+
+  const seenPbis = new Set<string>()
+
+  for (const [pbiId, intent] of Object.entries(draft.pbiIntent)) {
+    if (intent === 'all') {
+      seenPbis.add(pbiId)
+      const summary = pbiSummary[pbiId]
+      const override = draft.storyOverrides[pbiId]
+      if (!summary) {
+        hasUnknownTotal = true
+        continue
+      }
+      const removed = override?.remove.length ?? 0
+      storyCount += Math.max(0, summary.totalStoryCount - removed)
+    }
+  }
+
+  for (const [pbiId, override] of Object.entries(draft.storyOverrides)) {
+    if (override.add.length === 0) continue
+    seenPbis.add(pbiId)
+    storyCount += override.add.length
+  }
+
+  pbiCount = seenPbis.size
+  return { pbiCount, storyCount, hasUnknownTotal }
+}
+
+export function SprintDefinitionBanner({
+  productId,
+  draft,
+}: SprintDefinitionBannerProps) {
+  const clearPendingSprintDraft = useUserSettingsStore(
+    (s) => s.clearPendingSprintDraft,
+  )
+  const pbiSummary = useProductWorkspaceStore((s) => s.sprintMembership.pbiSummary)
+  const [isPending, startTransition] = useTransition()
+  const [confirmCancel, setConfirmCancel] = useState(false)
+
+  const counts = useMemo(
+    () => computeCounts(draft, pbiSummary),
+    [draft, pbiSummary],
+  )
+
+  function handleCancel() {
+    setConfirmCancel(true)
+  }
+
+  function confirmCancelAction() {
+    setConfirmCancel(false)
+    startTransition(async () => {
+      try {
+        await clearPendingSprintDraft(productId)
+      } catch (err) {
+        const message =
+          err instanceof Error ? err.message : 'Annuleren mislukt'
+        toast.error(message)
+      }
+    })
+  }
+
+  function handleCreate() {
+    // PBI-79 ST-1339 wires de createSprintWithSelectionAction in.
+    toast.info(
+      'Sprint aanmaken is nog niet aangesloten (wordt afgerond in ST-1339).',
+    )
+  }
+
+  const storyLabel = counts.hasUnknownTotal
+    ? `${counts.storyCount}+`
+    : counts.storyCount
+  const pbiSuffix = counts.pbiCount === 1 ? '' : "'s"
+
+  return (
+    <div
+      className="sticky top-0 z-30 bg-tertiary-container text-tertiary-container-foreground border-b border-tertiary px-4 py-2.5 flex items-center gap-4"
+      {...debugProps('sprint-definition-banner')}
+    >
+      <div className="flex-1 min-w-0">
+        <div className="flex items-baseline gap-2">
+          <span className="text-sm font-medium shrink-0">
+            Sprint definiëren —
+          </span>
+          <span className="text-sm truncate" title={draft.goal}>
+            {draft.goal}
+          </span>
+        </div>
+        <div className="text-xs opacity-80 mt-0.5">
+          {counts.pbiCount} PBI{pbiSuffix} · {storyLabel} stor
+          {counts.storyCount === 1 ? 'y' : 'ies'} geselecteerd
+        </div>
+      </div>
+      <div className="flex items-center gap-2 shrink-0">
+        <Button
+          type="button"
+          variant="ghost"
+          onClick={handleCancel}
+          disabled={isPending}
+          data-debug-id="sprint-definition-banner__cancel"
+        >
+          Annuleren
+        </Button>
+        <Button
+          type="button"
+          onClick={handleCreate}
+          disabled={isPending || counts.pbiCount === 0}
+          data-debug-id="sprint-definition-banner__create"
+        >
+          Sprint aanmaken
+        </Button>
+      </div>
+      <AlertDialog open={confirmCancel} onOpenChange={setConfirmCancel}>
+        <AlertDialogContent size="sm">
+          <AlertDialogHeader>
+            <AlertDialogTitle>Sprint-definitie annuleren?</AlertDialogTitle>
+            <AlertDialogDescription>
+              Je conceptselectie gaat verloren. Het sprint-doel en de
+              gemarkeerde PBI/stories worden verwijderd.
+            </AlertDialogDescription>
+          </AlertDialogHeader>
+          <AlertDialogFooter>
+            <AlertDialogCancel onClick={() => setConfirmCancel(false)}>
+              Doorgaan
+            </AlertDialogCancel>
+            <AlertDialogAction
+              variant="destructive"
+              onClick={confirmCancelAction}
+            >
+              Ja, annuleren
+            </AlertDialogAction>
+          </AlertDialogFooter>
+        </AlertDialogContent>
+      </AlertDialog>
+    </div>
+  )
+}
diff --git a/components/backlog/sprint-draft-banner.tsx b/components/backlog/sprint-draft-banner.tsx
new file mode 100644
index 0000000..3d3b9ff
--- /dev/null
+++ b/components/backlog/sprint-draft-banner.tsx
@@ -0,0 +1,22 @@
+'use client'
+
+import { useUserSettingsStore } from '@/stores/user-settings/store'
+import { SprintDefinitionBanner } from './sprint-definition-banner'
+
+interface SprintDraftBannerProps {
+  productId: string
+}
+
+/**
+ * PBI-79 / ST-1337: client-wrapper die de SprintDefinitionBanner alleen rendert
+ * als er een pendingSprintDraft voor dit product staat. Hydratatie loopt via
+ * UserSettingsBridge — dit component subscribt op die store en is daarmee
+ * automatisch reactief op draft-mutaties (set/clear).
+ */
+export function SprintDraftBanner({ productId }: SprintDraftBannerProps) {
+  const draft = useUserSettingsStore(
+    (s) => s.entities.settings.workflow?.pendingSprintDraft?.[productId],
+  )
+  if (!draft) return null
+  return <SprintDefinitionBanner productId={productId} draft={draft} />
+}
diff --git a/components/backlog/story-panel.tsx b/components/backlog/story-panel.tsx
index e16d23a..853c8b4 100644
--- a/components/backlog/story-panel.tsx
+++ b/components/backlog/story-panel.tsx
@@ -21,6 +21,13 @@ import {
 } from '@dnd-kit/sortable'
 import { CSS } from '@dnd-kit/utilities'
 import { toast } from 'sonner'
+import { CheckSquare, Square } from 'lucide-react'
+import {
+  Tooltip,
+  TooltipContent,
+  TooltipProvider,
+  TooltipTrigger,
+} from '@/components/ui/tooltip'
 import { Button } from '@/components/ui/button'
 import { Badge } from '@/components/ui/badge'
 import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select'
@@ -28,7 +35,10 @@ import { PanelNavBar } from '@/components/shared/panel-nav-bar'
 import { useShallow } from 'zustand/react/shallow'
 import { useUserSettingsStore } from '@/stores/user-settings/store'
 import { useProductWorkspaceStore } from '@/stores/product-workspace/store'
-import { selectStoriesForActivePbi } from '@/stores/product-workspace/selectors'
+import {
+  selectStoriesForActivePbi,
+  selectStoryIsBlocked,
+} from '@/stores/product-workspace/selectors'
 import type { BacklogStory as WorkspaceStory } from '@/stores/product-workspace/types'
 import { reorderStoriesAction } from '@/actions/stories'
 import { StoryDialog, type StoryDialogState } from './story-dialog'
@@ -73,11 +83,17 @@ interface StoryPanelProps {
 function SortableStoryBlock({
   story,
   isSelected,
+  cherrypick,
   onSelect,
   onEdit,
 }: {
   story: Story
   isSelected: boolean
+  cherrypick: {
+    checked: boolean
+    blocked: { sprintName: string } | null
+    onToggle: () => void
+  } | null
   onSelect: () => void
   onEdit: () => void
 }) {
@@ -109,21 +125,75 @@ function SortableStoryBlock({
         </Badge>
       }
       actions={
-        <button
-          onClick={(e) => { e.stopPropagation(); onEdit() }}
-          className="inline-flex items-center justify-center min-h-7 min-w-7 text-muted-foreground hover:text-foreground rounded transition-colors"
-          aria-label="Story bewerken"
-        >
-          <svg className="size-3.5" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
-            <path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7" />
-            <path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4 9.5-9.5z" />
-          </svg>
-        </button>
+        <div className="flex items-center gap-1">
+          {cherrypick && <StoryCherrypickButton {...cherrypick} />}
+          <button
+            onClick={(e) => { e.stopPropagation(); onEdit() }}
+            className="inline-flex items-center justify-center min-h-7 min-w-7 text-muted-foreground hover:text-foreground rounded transition-colors"
+            aria-label="Story bewerken"
+          >
+            <svg className="size-3.5" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round">
+              <path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7" />
+              <path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4 9.5-9.5z" />
+            </svg>
+          </button>
+        </div>
       }
     />
   )
 }
 
+function StoryCherrypickButton({
+  checked,
+  blocked,
+  onToggle,
+}: {
+  checked: boolean
+  blocked: { sprintName: string } | null
+  onToggle: () => void
+}) {
+  const icon = checked ? (
+    <CheckSquare size={16} className="text-primary" />
+  ) : (
+    <Square size={16} />
+  )
+  if (blocked) {
+    return (
+      <TooltipProvider>
+        <Tooltip>
+          <TooltipTrigger
+            data-disabled="true"
+            aria-disabled="true"
+            onClick={(e) => e.stopPropagation()}
+            className="inline-flex items-center justify-center min-h-7 min-w-7 rounded opacity-40 cursor-not-allowed text-muted-foreground"
+          >
+            {icon}
+          </TooltipTrigger>
+          <TooltipContent>Zit in sprint {blocked.sprintName}</TooltipContent>
+        </Tooltip>
+      </TooltipProvider>
+    )
+  }
+  return (
+    <button
+      onClick={(e) => {
+        e.stopPropagation()
+        onToggle()
+      }}
+      aria-pressed={checked}
+      aria-label={
+        checked ? 'Story uit sprint halen' : 'Story aan sprint toevoegen'
+      }
+      className={cn(
+        'inline-flex items-center justify-center min-h-7 min-w-7 rounded transition-colors',
+        'text-muted-foreground hover:text-foreground',
+      )}
+    >
+      {icon}
+    </button>
+  )
+}
+
 // --- Main component ---
 // PBI-74 / T-850: leest stories voor active PBI via selectStoriesForActivePbi
 // (useShallow). DnD via applyOptimisticMutation('story-order').
@@ -300,9 +370,10 @@ export function StoryPanel({ productId, isDemo }: StoryPanelProps) {
             <SortableContext items={filtered.map(s => s.id)} strategy={rectSortingStrategy}>
               <div className="grid grid-cols-3 gap-2">
                 {filtered.map(story => (
-                  <SortableStoryBlock
+                  <StoryBlockWithCherrypick
                     key={story.id}
                     story={story}
+                    productId={productId}
                     isSelected={selectedStoryId === story.id}
                     onSelect={() => useProductWorkspaceStore.getState().setActiveStory(story.id)}
                     onEdit={() => setStoryDialogState({ mode: 'edit', story, productId })}
@@ -332,3 +403,76 @@ export function StoryPanel({ productId, isDemo }: StoryPanelProps) {
     </div>
   )
 }
+
+// PBI-79 / ST-1337: wrapper rond SortableStoryBlock met cherrypick-handling.
+// Subscribed per story zodat enkel de relevante rij re-rendert bij draft- of
+// crossSprintBlocks-mutaties.
+function StoryBlockWithCherrypick({
+  story,
+  productId,
+  isSelected,
+  onSelect,
+  onEdit,
+}: {
+  story: Story
+  productId: string
+  isSelected: boolean
+  onSelect: () => void
+  onEdit: () => void
+}) {
+  const draft = useUserSettingsStore(
+    (s) => s.entities.settings.workflow?.pendingSprintDraft?.[productId],
+  )
+  const upsertStoryOverride = useUserSettingsStore((s) => s.upsertStoryOverride)
+  const blocked = useProductWorkspaceStore((s) =>
+    selectStoryIsBlocked(s, story.id),
+  )
+
+  const cherrypick = draft
+    ? (() => {
+        const intent = draft.pbiIntent[story.pbi_id] ?? 'none'
+        const override = draft.storyOverrides[story.pbi_id] ?? {
+          add: [],
+          remove: [],
+        }
+        const checked =
+          (intent === 'all' && !override.remove.includes(story.id)) ||
+          override.add.includes(story.id)
+        const onToggle = () => {
+          // Resolve next state to cancel-out cleanly.
+          if (intent === 'all') {
+            // Default = checked; toggling means "remove this story from sprint".
+            const isCurrentlyChecked = checked
+            void upsertStoryOverride(
+              productId,
+              story.pbi_id,
+              story.id,
+              isCurrentlyChecked ? 'remove' : 'clear',
+            )
+          } else {
+            void upsertStoryOverride(
+              productId,
+              story.pbi_id,
+              story.id,
+              checked ? 'clear' : 'add',
+            )
+          }
+        }
+        return {
+          checked,
+          blocked: blocked ? { sprintName: blocked.sprintName } : null,
+          onToggle,
+        }
+      })()
+    : null
+
+  return (
+    <SortableStoryBlock
+      story={story}
+      isSelected={isSelected}
+      cherrypick={cherrypick}
+      onSelect={onSelect}
+      onEdit={onEdit}
+    />
+  )
+}
diff --git a/lib/user-settings.ts b/lib/user-settings.ts
index 3abcb0a..5139261 100644
--- a/lib/user-settings.ts
+++ b/lib/user-settings.ts
@@ -57,8 +57,8 @@ const StoryOverrides = z.object({
 
 const PendingSprintDraftSchema = z.object({
   goal: z.string().min(1),
-  startAt: z.string().datetime().optional(),
-  endAt: z.string().datetime().optional(),
+  startAt: z.string().date().optional(),
+  endAt: z.string().date().optional(),
   pbiIntent: z.record(z.string(), PbiIntent).default({}),
   storyOverrides: z.record(z.string(), StoryOverrides).default({}),
 }).strict()