From dc0109dd06afc05520efcb60e06ca8cc884c0338 Mon Sep 17 00:00:00 2001
From: Thomas Kaul <4159106+dtslvr@users.noreply.github.com>
Date: Thu, 8 Oct 2026 14:41:12 +0200
Subject: [PATCH] Fix end date of calendar year date ranges

---
 .../calculator/portfolio-calculator.ts        |  9 +++-
 .../roai/portfolio-calculator.spec.ts         | 44 +++++++++++++++++++
 2 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/apps/api/src/app/portfolio/calculator/portfolio-calculator.ts b/apps/api/src/app/portfolio/calculator/portfolio-calculator.ts
index 7a8bbcc741..1527c4bd3b 100644
--- a/apps/api/src/app/portfolio/calculator/portfolio-calculator.ts
+++ b/apps/api/src/app/portfolio/calculator/portfolio-calculator.ts
@@ -1407,7 +1407,7 @@ export abstract class PortfolioCalculator {
     return this.snapshot.totalLiabilitiesWithCurrencyEffect;
   }
 
-  public async getPerformance({ end, start }) {
+  public async getPerformance({ end, start }: { end: Date; start: Date }) {
     await this.snapshotPromise;
 
     const { historicalData } = this.snapshot;
@@ -1418,6 +1418,11 @@ export abstract class PortfolioCalculator {
     let netPerformanceAtStartDate: number;
     let netPerformanceWithCurrencyEffectAtStartDate: number;
 
+    // The historical data items are dated at midnight in UTC, hence a start
+    // or an end at the end of a day in the time zone of the instance is
+    // changed to this date
+    const endDate = isEqual(end, endOfDay(end)) ? resetHours(end) : end;
+
     const startDate = isEqual(start, endOfDay(start))
       ? resetHours(start)
       : start;
@@ -1425,7 +1430,7 @@ export abstract class PortfolioCalculator {
     for (const historicalDataItem of historicalData) {
       const date = resetHours(parseDate(historicalDataItem.date));
 
-      if (!isBefore(date, startDate) && !isAfter(date, end)) {
+      if (!isBefore(date, startDate) && !isAfter(date, endDate)) {
         // Take the values at the start date from the first day of the date
         // range
         if (historicalDataItemsOfDateRange.length === 0) {
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 5f8d9cdc44..9589132372 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
@@ -9,6 +9,7 @@ import { ConfigurationService } from '@ghostfolio/api/services/configuration/con
 import { ExchangeRateDataService } from '@ghostfolio/api/services/exchange-rate-data/exchange-rate-data.service';
 import { PortfolioSnapshotService } from '@ghostfolio/api/services/queues/portfolio-snapshot/portfolio-snapshot.service';
 import { PortfolioSnapshotServiceMock } from '@ghostfolio/api/services/queues/portfolio-snapshot/portfolio-snapshot.service.mock';
+import { getIntervalFromDateRange } from '@ghostfolio/common/calculation-helper';
 import { HistoricalDataItem } from '@ghostfolio/common/interfaces';
 import { PerformanceCalculationType } from '@ghostfolio/common/types/performance-calculation-type.type';
 
@@ -183,4 +184,47 @@ describe('PortfolioCalculator', () => {
       ).toBeCloseTo(0.23, 10);
     });
   });
+
+  describe('get performance', () => {
+    // The chart items are dated at midnight in UTC, but a calendar year date
+    // range ends at the end of 31 December in the time zone of the instance.
+    // Hence this test must give the same result with the instance in any time
+    // zone. Set TEST_TZ to run it with the instance in another time zone.
+    it('with a calendar year date range', async () => {
+      const snapshot = await portfolioCalculator.getSnapshot();
+
+      snapshot.historicalData = [
+        getHistoricalDataItem({
+          date: '2016-12-31',
+          investment: 100,
+          netPerformance: 0
+        }),
+        getHistoricalDataItem({
+          date: '2017-12-31',
+          investment: 100,
+          netPerformance: 10
+        }),
+        getHistoricalDataItem({
+          date: '2018-01-01',
+          investment: 100,
+          netPerformance: 20
+        })
+      ];
+
+      const { endDate, startDate } = getIntervalFromDateRange({
+        dateRange: '2017'
+      });
+
+      const { chart } = await portfolioCalculator.getPerformance({
+        end: endDate,
+        start: startDate
+      });
+
+      expect(
+        chart.map(({ date }) => {
+          return date;
+        })
+      ).toEqual(['2016-12-31', '2017-12-31']);
+    });
+  });
 });