fix date test

client/packages/common/src/intl/utils/DateUtils.test.ts

@@ -18,6 +18,7 @@ describe('getDisplayAge', () => {
   const hookResult = renderHookWithProvider(() => useFormatDateTime());
   const { getDisplayAge } = hookResult.result.current;
   const today = new Date();
+
   it('returns age in years when patient is over 1 year or 1 year old', () => {
     const dob = DateUtils.addYears(today, -9);
     const result = getDisplayAge(dob);
@@ -26,9 +27,12 @@ describe('getDisplayAge', () => {
 
   it('returns age in months and days when patient is less than 1 year old', () => {
     const threeMonthsAgo = DateUtils.addMonths(today, -3);
+    const dayOffset =
+      DateUtils.getDaysInMonth(today) -
+      DateUtils.getDaysInMonth(threeMonthsAgo);
     const dob = DateUtils.addDays(threeMonthsAgo, -2);
     const result = getDisplayAge(dob);
-    expect(result).toBe('3 months, 2 days');
+    expect(result).toBe(`3 months, ${2 + dayOffset} days`);
   });
 
   it('returns age in days when patient is less than 1 month old', () => {

client/packages/common/src/intl/utils/DateUtils.ts

@@ -10,6 +10,7 @@ import {
   differenceInMonths,
   differenceInMinutes,
   differenceInYears,
+  getDaysInMonth,
   isPast,
   isFuture,
   isThisWeek,
@@ -104,6 +105,7 @@ export const DateUtils = {
         : new Date(date);
     return isValid(maybeDate) ? maybeDate : null;
   },
+  getDaysInMonth,
   /**
    * While getDateOrNull is naive to the timezone, the timezone will still
    * change. When converting from the assumed naive zone of GMT to the local