diff --git a/gnome/prefs.js b/gnome/prefs.js
index 8d80679..b0d13f9 100644
--- a/gnome/prefs.js
+++ b/gnome/prefs.js
@@ -26,7 +26,7 @@ const PERIODS = [
   { id: 'week', label: '7 Days' },
   { id: '30days', label: '30 Days' },
   { id: 'month', label: 'Month' },
-  { id: 'all', label: 'All Time' },
+  { id: 'all', label: '6 Months' },
 ];
 
 export default class CodeBurnPreferences extends ExtensionPreferences {
diff --git a/src/cli-date.ts b/src/cli-date.ts
index b3d502d..7dfd06f 100644
--- a/src/cli-date.ts
+++ b/src/cli-date.ts
@@ -113,7 +113,7 @@ export function getDateRange(period: string): { range: DateRange; label: string
       return { range: { start, end }, label: 'Last 30 Days' }
     }
     case 'all': {
-      const start = new Date(now.getFullYear(), now.getMonth() - ALL_TIME_MONTHS, now.getDate())
+      const start = new Date(now.getFullYear(), now.getMonth() - ALL_TIME_MONTHS, 1)
       return { range: { start, end }, label: 'Last 6 months' }
     }
     default: {
diff --git a/src/dashboard.tsx b/src/dashboard.tsx
index 16aea07..3193b5a 100644
--- a/src/dashboard.tsx
+++ b/src/dashboard.tsx
@@ -13,7 +13,7 @@ import { dateKey } from './day-aggregator.js'
 import { CompareView } from './compare.js'
 import { getPlanUsageOrNull, type PlanUsage } from './plan-usage.js'
 import { planDisplayName } from './plans.js'
-import { getDateRange as getDateRangeShared, PERIODS, PERIOD_LABELS, type Period } from './cli-date.js'
+import { getDateRange, PERIODS, PERIOD_LABELS, type Period } from './cli-date.js'
 import { join } from 'path'
 import { patchStdoutForWindows } from './ink-win.js'
 
@@ -96,7 +96,7 @@ function gradientColor(pct: number): string {
 }
 
 function getPeriodRange(period: Period): { start: Date; end: Date } {
-  return getDateRangeShared(period).range
+  return getDateRange(period).range
 }
 
 type Layout = { dashWidth: number; wide: boolean; halfWidth: number; barWidth: number }
diff --git a/tests/cli-date.test.ts b/tests/cli-date.test.ts
index f2f7404..e30096d 100644
--- a/tests/cli-date.test.ts
+++ b/tests/cli-date.test.ts
@@ -1,4 +1,4 @@
-import { describe, it, expect } from 'vitest'
+import { afterEach, describe, it, expect, vi } from 'vitest'
 import {
   getDateRange,
   PERIODS,
@@ -7,6 +7,10 @@ import {
   type Period,
 } from '../src/cli-date.js'
 
+afterEach(() => {
+  vi.useRealTimers()
+})
+
 describe('getDateRange', () => {
   it('"all" is bounded to the last 6 months, not epoch', () => {
     const { range, label } = getDateRange('all')
@@ -18,27 +22,26 @@ describe('getDateRange', () => {
     // dashboard bug) or any pre-2000 date.
     expect(range.start.getFullYear()).toBeGreaterThan(2000)
 
-    // Roughly 6 months back. Accept 5-7 months to absorb end-of-month
-    // clamping (e.g. on May 31, JS rolls Nov 31 -> Dec 1, shifting the
-    // computed month forward by one).
     const monthsDiff =
       (now.getFullYear() - range.start.getFullYear()) * 12 +
       (now.getMonth() - range.start.getMonth())
-    expect(monthsDiff).toBeGreaterThanOrEqual(5)
-    expect(monthsDiff).toBeLessThanOrEqual(7)
+    expect(monthsDiff).toBe(6)
+    expect(range.start.getDate()).toBe(1)
 
     // End is today, end of day.
     expect(range.end.getHours()).toBe(23)
     expect(range.end.getMinutes()).toBe(59)
   })
 
-  it('CLI and dashboard agree on "all" semantics (no Date(0) drift)', () => {
-    const a = getDateRange('all')
-    const b = getDateRange('all')
-    expect(a.range.start.getTime()).toBe(b.range.start.getTime())
-    expect(a.label).toBe(b.label)
-    // Regression guard: must never silently fall back to epoch.
-    expect(a.range.start.getFullYear()).toBeGreaterThan(2000)
+  it('"all" does not overflow past the target month at end-of-month', () => {
+    vi.useFakeTimers()
+    vi.setSystemTime(new Date(2026, 7, 31, 12, 0, 0))
+
+    const { range } = getDateRange('all')
+
+    expect(range.start.getFullYear()).toBe(2026)
+    expect(range.start.getMonth()).toBe(1)
+    expect(range.start.getDate()).toBe(1)
   })
 
   it('"week" returns the last 7 days', () => {