diff --git a/app/utils/chart-data-buckets.ts b/app/utils/chart-data-buckets.ts
index 1165c4541f..1cc4a43308 100644
--- a/app/utils/chart-data-buckets.ts
+++ b/app/utils/chart-data-buckets.ts
@@ -34,17 +34,13 @@ export function buildWeeklyEvolution(
   if (sorted.length === 0) return []
 
   const rangeStartDate = parseIsoDate(rangeStartIso)
+  const rangeEndDate = parseIsoDate(rangeEndIso)
 
-  // Align from last day with actual data (npm has 1-2 day delay, today is incomplete)
-  const lastNonZero = sorted.findLast(d => d.value > 0)
-  const pickerEnd = parseIsoDate(rangeEndIso)
-  const effectiveEnd = lastNonZero ? parseIsoDate(lastNonZero.day) : pickerEnd
-  const rangeEndDate = effectiveEnd.getTime() < pickerEnd.getTime() ? effectiveEnd : pickerEnd
-
-  // Group into 7-day buckets from END backwards
   const buckets = new Map<number, number>()
+
   for (const item of sorted) {
-    const offset = Math.floor((rangeEndDate.getTime() - parseIsoDate(item.day).getTime()) / DAY_MS)
+    const itemDate = parseIsoDate(item.day)
+    const offset = Math.floor((rangeEndDate.getTime() - itemDate.getTime()) / DAY_MS)
     if (offset < 0) continue
     const idx = Math.floor(offset / 7)
     buckets.set(idx, (buckets.get(idx) ?? 0) + item.value)
diff --git a/test/unit/app/utils/chart-data-buckets.spec.ts b/test/unit/app/utils/chart-data-buckets.spec.ts
index 8538f18138..141a9688c3 100644
--- a/test/unit/app/utils/chart-data-buckets.spec.ts
+++ b/test/unit/app/utils/chart-data-buckets.spec.ts
@@ -84,7 +84,7 @@ describe('buildWeeklyEvolution', () => {
     expect(result[1]!.weekEnd).toBe('2025-03-10')
   })
 
-  it('aligns from last non-zero data day, ignoring trailing zeros', () => {
+  it('always aligns from rangeEnd, even with trailing zeros', () => {
     const daily = [
       { day: '2025-03-01', value: 10 },
       { day: '2025-03-02', value: 10 },
@@ -99,10 +99,14 @@ describe('buildWeeklyEvolution', () => {
 
     const result = buildWeeklyEvolution(daily, '2025-03-01', '2025-03-09')
 
-    expect(result).toHaveLength(1)
-    expect(result[0]!.value).toBe(70)
+    // Bucket 0: 03-03..03-09 = 50, Bucket 1: 03-01..03-02 (partial, scaled)
+    expect(result).toHaveLength(2)
     expect(result[0]!.weekStart).toBe('2025-03-01')
-    expect(result[0]!.weekEnd).toBe('2025-03-07')
+    expect(result[0]!.weekEnd).toBe('2025-03-02')
+    expect(result[0]!.value).toBe(Math.round((20 * 7) / 2))
+    expect(result[1]!.weekStart).toBe('2025-03-03')
+    expect(result[1]!.weekEnd).toBe('2025-03-09')
+    expect(result[1]!.value).toBe(50)
   })
 
   it('returns empty array for empty input', () => {