fix(datetime): min/max correctly display available day periods (#26241)

Resolves #26216

core/src/components/datetime/test/data.spec.ts

@@ -205,6 +205,36 @@ describe('generateTime()', () => {
     expect(minutes).toStrictEqual([10, 15, 20]);
   });
 
+  it('should allow both am/pm when min is am and max is pm', () => {
+    // https://github.com/ionic-team/ionic-framework/issues/26216
+    const today = {
+      day: 22,
+      month: 5,
+      year: 2021,
+      hour: 5,
+      minute: 43,
+    };
+    const min = {
+      day: 22,
+      month: 5,
+      year: 2021,
+      hour: 11,
+      minute: 14,
+    };
+    const max = {
+      day: 22,
+      month: 5,
+      year: 2021,
+      hour: 12,
+      minute: 14,
+    };
+
+    const { am, pm } = generateTime(today, 'h12', min, max);
+
+    expect(am).toBe(true);
+    expect(pm).toBe(true);
+  });
+
   describe('hourCycle is 23', () => {
     it('should return hours in 24 hour format', () => {
       const refValue = {

core/src/components/datetime/utils/data.ts

@@ -221,7 +221,7 @@ export const generateTime = (
           const convertedHour = refParts.ampm === 'pm' ? (hour + 12) % 24 : hour;
           return (use24Hour ? hour : convertedHour) <= maxParts.hour!;
         });
-        isPMAllowed = maxParts.hour >= 13;
+        isPMAllowed = maxParts.hour >= 12;
       }
       if (maxParts.minute !== undefined && refParts.hour === maxParts.hour) {
         // The available minutes should only be filtered when the hour is the same as the max hour.
@@ -533,7 +533,7 @@ export const getTimeColumnsData = (
   minParts?: DatetimeParts,
   maxParts?: DatetimeParts,
   allowedHourValues?: number[],
-  allowedMinuteVaues?: number[]
+  allowedMinuteValues?: number[]
 ): { [key: string]: PickerColumnItem[] } => {
   const use24Hour = is24Hour(locale, hourCycle);
   const { hours, minutes, am, pm } = generateTime(
@@ -542,7 +542,7 @@ export const getTimeColumnsData = (
     minParts,
     maxParts,
     allowedHourValues,
-    allowedMinuteVaues
+    allowedMinuteValues
   );
 
   const hoursItems = hours.map((hour) => {