Avoiding Input Issues with MatDatepicker in Angular

When using the Angular Material Datepicker (MatDatepicker), developers often face formatting challenges, especially when dates are manually input by the user. The material-moment-adapter provides an elegant solution to handle these issues.

1. Date Format Issue During Manual Input

When using the MatDatepicker, if a user manually enters a date in the format dd/mm/yyyy (french format date) and the focus changes, the date might automatically be interpreted as the yyyy-dd-mm format. This unexpected transformation can lead to confusion and input errors. To address this behavior, we can configure a custom date format with MomentDateAdapter.

2. Timezone Conversion Issues with GMT +1

Another common issue faced is when the date 12/06/2023 00:00:00 becomes 11/06/2023 23:00:00 due to GMT +1 timezone conversion. This unintended shift can cause confusion and inaccuracies.

The solution is to utilize the useUtc: true option provided by the material-moment-adapter. When this option is set to true, dates won’t undergo undesired timezone adjustments.

Implementation Guide

• Install the necessary dependencies:

npm install @angular/material-moment-adapter moment

• In your module configuration, import the necessary modules and provide custom date format:

import { MomentDateAdapter, MAT_MOMENT_DATE_ADAPTER_OPTIONS } from '@angular/material-moment-adapter';

export const CUSTOM_DATE_FORMAT = {
  parse: {
    dateInput: 'DD/MM/YYYY',
  },
  display: {
    dateInput: 'DD/MM/YYYY',
    monthYearLabel: 'MMMM YYYY',
    dateA11yLabel: 'DD/MM/YYYY',
    monthYearA11yLabel: 'MMMM YYYY',
  },
};

@NgModule({
  ...
  providers: [
    { provide: MAT_DATE_LOCALE, useValue: 'fr-FR' },
    { provide: MAT_DATE_FORMATS, useValue: CUSTOM_DATE_FORMAT },
    { provide: DateAdapter, useClass: MomentDateAdapter },
    { provide: MAT_MOMENT_DATE_ADAPTER_OPTIONS, useValue: { useUtc: true } },
  ],
  ...
})

• With the above configuration, MatDatepicker will now correctly interpret manually entered dates and avoid unwanted timezone transformations.

Conclusion

The Angular Material Datepicker is a versatile component, but it’s essential to handle date formatting and timezone issues for a seamless user experience. By leveraging material-moment-adapter and the configurations outlined above, developers can ensure consistent and accurate date input and display.