doneit-web/src/app/pages/agenda/custom-date-formatter.provider.ts

import { CalendarDateFormatter, DateFormatterParams } from 'angular-calendar';
import { formatDate } from '@angular/common';
import { Injectable } from '@angular/core';

@Injectable()
export class CustomDateFormatter extends CalendarDateFormatter {
  // you can override any of the methods defined in the parent class

  public dayViewHour({ date, locale }: DateFormatterParams): string {
    return formatDate(date, 'HH', locale);
  }

  public weekViewHour({ date, locale }: DateFormatterParams): string {
    return this.dayViewHour({ date, locale });
  }
}