fix(UI): incorrect month showing in MAU

datahub-graphql-core/src/main/java/com/linkedin/datahub/graphql/analytics/resolver/GetChartsResolver.java

@@ -84,8 +84,21 @@ private TimeSeriesChart getActiveUsersTimeSeriesChart(
       final DateTime end,
       final String title,
       final DateInterval interval) {
-    final DateRange dateRange =
-        new DateRange(String.valueOf(beginning.getMillis()), String.valueOf(end.getMillis()));
+
+    final DateRange dateRange;
+
+    // adjust month to show 1st of month rather than last day of previous month
+    if (interval == DateInterval.MONTH) {
+      dateRange =
+          new DateRange(
+              String.valueOf(beginning.plusDays(1).getMillis()), // Shift start by 1 day
+              String.valueOf(end.plusDays(1).getMillis()) // Shift end by 1 day
+              );
+    } else {
+      // week display starting Sundays
+      dateRange =
+          new DateRange(String.valueOf(beginning.getMillis()), String.valueOf(end.getMillis()));
+    }
 
     final List<NamedLine> timeSeriesLines =
         _analyticsService.getTimeseriesChart(
@@ -96,6 +109,7 @@ private TimeSeriesChart getActiveUsersTimeSeriesChart(
             ImmutableMap.of(),
             Collections.emptyMap(),
             Optional.of("browserId"));
+
     return TimeSeriesChart.builder()
         .setTitle(title)
         .setDateRange(dateRange)

datahub-graphql-core/src/test/java/com/linkedin/datahub/graphql/utils/DateUtilTest.java

@@ -47,4 +47,26 @@ public void testStartOfNextWeek() {
     Mockito.when(dateUtil.getNow()).thenReturn(setTimeParts(8, false));
     assertEqualStartOfNextWeek(dateUtil, 9);
   }
+
+  // validates logic to display correct dates in MAU chart
+  @Test
+  public void testDateAdjustmentsForMonth() {
+    DateUtil dateUtil = Mockito.spy(DateUtil.class);
+
+    Mockito.when(dateUtil.getNow()).thenReturn(new DateTime(2024, 11, 15, 0, 0, 0));
+
+    // start date should be next month minus a day
+    // but we want to display Dec 1 instead of Nov 30, so add a day and verify it's Dec
+    DateTime startOfNextMonthMinus12 = dateUtil.getStartOfNextMonth().minusMonths(12);
+    DateTime adjustedStart = startOfNextMonthMinus12.minusMillis(1).plusDays(1);
+    assertEquals(12, adjustedStart.getMonthOfYear()); // Verify it is December
+    assertEquals(2023, adjustedStart.getYear()); // Verify it is 2023
+
+    // verify that the end date displays correctly
+    // the chart will display Oct 1 as the last month because we don't show current month
+    DateTime startOfThisMonth = dateUtil.getStartOfThisMonth();
+    DateTime adjustedEnd = startOfThisMonth.minusMillis(1).plusDays(1);
+    assertEquals(11, adjustedEnd.getMonthOfYear()); // Verify it is November
+    assertEquals(2024, adjustedEnd.getYear()); // Verify it is 2024
+  }
 }