Для календаря PrimeNG вы можете добавить локализацию к свойству locale.
HTML:
<p-calendar [(ngModel)]="dateValue" [locale]="en"></p-calendar>
TS
ngOnInit() {
this.en = {
firstDayOfWeek: 0,
dayNames: ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"],
dayNamesShort: ["Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"],
dayNamesMin: ["Su","Mo","Tu","We","Th","Fr","Sa"],
monthNames: [ "January","February","March","April","May","June","July","August","September","October","November","December" ],
monthNamesShort: [ "Jan", "Feb", "Mar", "Apr", "May", "Jun","Jul", "Aug", "Sep", "Oct", "Nov", "Dec" ],
today: 'Today',
clear: 'Clear',
dateFormat: 'mm/dd/yy',
weekHeader: 'Wk'
};
}
Ознакомьтесь с официальной документацией .