Fix timezone handling of stock split dates

apps/api/src/services/asset-profile-split/asset-profile-split.helper.spec.ts

@@ -2,6 +2,7 @@ import {
   activityDummyData,
   assetProfileDummyData
 } from '@ghostfolio/api/app/portfolio/calculator/portfolio-calculator-test-utils';
+import * as commonHelper from '@ghostfolio/common/helper';
 import { parseDate } from '@ghostfolio/common/helper';
 import { Activity } from '@ghostfolio/common/interfaces';
 
@@ -39,7 +40,7 @@ describe('adjustActivityBySplits', () => {
   });
 
   it('only adjusts activities before the split calendar date', () => {
-    const split = createSplit('2024-06-15T12:00:00Z', 2, 1);
+    const split = createSplit('2024-06-15T00:00:00Z', 2, 1);
     const activityOnSplitDate = createActivity('2024-06-15T18:00:00Z');
     const activityAfterSplit = createActivity('2024-06-16T00:00:00Z');
 
@@ -57,6 +58,23 @@ describe('adjustActivityBySplits', () => {
     expect(adjustedActivityAfterSplit).toEqual(activityAfterSplit);
     expect(adjustedActivityAfterSplit).not.toBe(activityAfterSplit);
   });
+
+  it('compares stored UTC split dates without normalizing them locally', () => {
+    const resetHoursSpy = jest
+      .spyOn(commonHelper, 'resetHours')
+      .mockReturnValue(new Date('2024-06-14T00:00:00Z'));
+
+    try {
+      const activity = createActivity('2024-06-14T12:00:00Z');
+      const split = createSplit('2024-06-15T00:00:00Z', 2, 1);
+
+      const adjustedActivity = adjustActivityBySplits(activity, [split]);
+
+      expect(adjustedActivity.quantity).toBe(20);
+    } finally {
+      resetHoursSpy.mockRestore();
+    }
+  });
 });
 
 function createActivity(date: string): Activity {

apps/api/src/services/asset-profile-split/asset-profile-split.helper.ts

@@ -13,7 +13,7 @@ export function adjustActivityBySplits(
   let splitFactor = new Big(1);
 
   for (const split of splits) {
-    if (isBefore(activityDate, resetHours(split.date))) {
+    if (isBefore(activityDate, split.date)) {
       splitFactor = splitFactor.mul(split.numerator).div(split.denominator);
     }
   }