bug(datepicker): Localized date format issue

[LuisTovar0]

MatDatepicker seems to not accept dates in dd/mm/yyyy format, even when the MAT_DATE_LOCALE and DateAdapter's locale are set to a language/locale where this format is the standard.

I have noticed that this problem can be circumvented with the MomentJS date adapter for Angular, but it shouldn't be required since it's expected behaviour.

Reproduction

StackBlitz link: https://stackblitz.com/edit/stackblitz-starters-4gjjc1ce?file=src%2Fapp%2Fapp.component.ts

Steps to reproduce:

1. Select pt-PT or fr-FR
2. Type "15/12/2024" in the datepicker and hit tab
3. Now type "12/15/2024" and hit tab

Expected Behavior

In step 2, the datepicker should consider that a valid date
In step 3, the datepicker should not consider that a valid date

Actual Behavior

In step 2, the datepicker considers the date invalid
In step 3, the datepicker changes the string to 15/12/2024, making it become valid

Environment

Angular CLI: 19.2.7
CDK/Material:19.2.9
Node: 20.19.0
Package Manager: pnpm 8.15.6
OS: linux x64

[crisbeto]

This is due to the default date adapter. From the docs:

Please note: provideNativeDateAdapter is based off the functionality available in JavaScript's native Date object. Thus it is not suitable for many locales. One of the biggest shortcomings of the native Date object is the inability to set the parse format. We strongly recommend using an adapter based on a more robust formatting and parsing library. You can use provideMomentDateAdapter or a custom DateAdapter that works with the library of your choice.

You can provide an alternate adapter if you need something more robust: https://material.angular.io/components/datepicker/overview#choosing-a-date-implementation-and-date-format-settings