From 4193e8814ac95f94189c6e6aa2b14b6bbbc8c646 Mon Sep 17 00:00:00 2001
From: Thomas Kaul <4159106+dtslvr@users.noreply.github.com>
Date: Sat, 10 Oct 2026 20:19:10 +0200
Subject: [PATCH] Fix start date of date ranges for instances in time zones
 with negative UTC offset

---
 .../calculator/roai/portfolio-calculator.spec.ts    | 13 ++++++++-----
 apps/api/src/app/portfolio/portfolio.service.ts     | 10 ++++++++--
 libs/common/src/lib/calculation-helper.spec.ts      |  6 ++++--
 3 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator.spec.ts b/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator.spec.ts
index 9e0fbc701f..c2779c2c14 100644
--- a/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator.spec.ts
+++ b/apps/api/src/app/portfolio/calculator/roai/portfolio-calculator.spec.ts
@@ -190,6 +190,10 @@ describe('PortfolioCalculator', () => {
   });
 
   describe('get performance', () => {
+    afterEach(() => {
+      jest.useRealTimers();
+    });
+
     it('with a calendar year date range', async () => {
       const snapshot = await portfolioCalculator.getSnapshot();
 
@@ -242,13 +246,14 @@ describe('PortfolioCalculator', () => {
           netPerformance: 10
         }),
         getHistoricalDataItem({
-          date: '2017-01-03',
+          date: '2017-01-01',
           investment: 100,
           netPerformance: 20
         })
       ];
 
-      jest.useFakeTimers().setSystemTime(new Date('2017-01-04T02:30:00.000Z'));
+      // 1 January 2017, 10:00 in New York
+      jest.useFakeTimers().setSystemTime(new Date('2017-01-01T15:00:00.000Z'));
 
       const { endDate, startDate } = getIntervalFromDateRange({
         dateRange: 'ytd'
@@ -259,13 +264,11 @@ describe('PortfolioCalculator', () => {
         start: startDate
       });
 
-      jest.useRealTimers();
-
       expect(
         chart.map(({ date }) => {
           return date;
         })
-      ).toEqual(['2016-12-31', '2017-01-03']);
+      ).toEqual(['2016-12-31', '2017-01-01']);
     });
   });
 });
diff --git a/apps/api/src/app/portfolio/portfolio.service.ts b/apps/api/src/app/portfolio/portfolio.service.ts
index 6e9f8c045a..ab2c0de2d4 100644
--- a/apps/api/src/app/portfolio/portfolio.service.ts
+++ b/apps/api/src/app/portfolio/portfolio.service.ts
@@ -47,6 +47,7 @@ import {
   isAccountExcluded,
   isDraftActivity,
   parseDate,
+  resetHours,
   resolveUserSettings
 } from '@ghostfolio/common/helper';
 import {
@@ -559,8 +560,13 @@ export class PortfolioService {
 
     const { historicalData } = await portfolioCalculator.getSnapshot();
 
-    const items = historicalData.filter(({ date }) => {
-      return !isBefore(date, startDate) && !isAfter(date, endDate);
+    const items = historicalData.filter((historicalDataItem) => {
+      const date = resetHours(parseDate(historicalDataItem.date));
+
+      return (
+        !isBefore(date, resetHours(startDate)) &&
+        !isAfter(date, resetHours(endDate))
+      );
     });
 
     let investments: InvestmentItem[];
diff --git a/libs/common/src/lib/calculation-helper.spec.ts b/libs/common/src/lib/calculation-helper.spec.ts
index a16e487431..7924d72544 100644
--- a/libs/common/src/lib/calculation-helper.spec.ts
+++ b/libs/common/src/lib/calculation-helper.spec.ts
@@ -10,6 +10,10 @@ import { DateRange } from './types';
 
 describe('CalculationHelper', () => {
   describe('interval from date range', () => {
+    afterEach(() => {
+      jest.useRealTimers();
+    });
+
     it('Get interval of a calendar year', async () => {
       const { endDate, startDate } = getIntervalFromDateRange({
         dateRange: '2024'
@@ -42,8 +46,6 @@ describe('CalculationHelper', () => {
         new Date(2023, 9, 10),
         new Date(2019, 9, 10)
       ]);
-
-      jest.useRealTimers();
     });
   });