fix(FOUR-33966): date picker doesn't allow to pick date when daylight savings change [54094].

src/components/FormDatePicker.vue

@@ -250,9 +250,11 @@ export default {
       return date;
     },
     parsingInputDate(val) {
-      const date = moment(val, this.format).local(true);
-      // Check if user is typing, if the date is not valid, let the user continue
+      const date = this.dataFormat === "date" ? moment.utc(val, this.format, true) : moment.tz(val, this.format, true, getTimezone());
       if (!date.isValid()) return "";
+      if (this.dataFormat === "date") {
+        return new Date(date.year(), date.month(), date.date());
+      }
       return date.toDate();
     },
     /*

tests/unit/FormDatePicker.spec.js

@@ -178,6 +178,58 @@ describe('FormDatePicker', () => {
       expect(wrapper.html()).not.toContain(validationError);
     });
 
+    it('keeps the selected calendar day on Melbourne DST start', () => {
+      const previousTz = process.env.TZ;
+      process.env.TZ = 'Australia/Melbourne';
+
+      try {
+        window.ProcessMaker.user = {
+          timezone: 'Australia/Melbourne',
+          datetime_format: 'MM/DD/YYYY',
+        };
+
+        const wrapper = mount(FormDatePicker, {
+          propsData: {
+            dataFormat: 'date',
+          },
+        });
+
+        const parsed = wrapper.vm.parsingInputDate('10/04/2026');
+
+        expect(parsed.getFullYear()).toBe(2026);
+        expect(parsed.getMonth()).toBe(9);
+        expect(parsed.getDate()).toBe(4);
+      } finally {
+        process.env.TZ = previousTz;
+      }
+    });
+
+    it('keeps the selected calendar day on New Zealand DST start', () => {
+      const previousTz = process.env.TZ;
+      process.env.TZ = 'Pacific/Auckland';
+
+      try {
+        window.ProcessMaker.user = {
+          timezone: 'Pacific/Auckland',
+          datetime_format: 'MM/DD/YYYY',
+        };
+
+        const wrapper = mount(FormDatePicker, {
+          propsData: {
+            dataFormat: 'date',
+          },
+        });
+
+        const parsed = wrapper.vm.parsingInputDate('09/27/2026');
+
+        expect(parsed.getFullYear()).toBe(2026);
+        expect(parsed.getMonth()).toBe(8);
+        expect(parsed.getDate()).toBe(27);
+      } finally {
+        process.env.TZ = previousTz;
+      }
+    });
+
     it('convert invalid value to current date', async () => {
       const wrapper = mount(FormDatePicker, {
         propsData: {