getRoundedTimestamp = millisecondsUTC => {
    if (!millisecondsUTC) {
      // no need to replace with UI5Date, as we don't use any non-UTC functions
      millisecondsUTC = new Date().getTime();
    }
    const rounded = millisecondsUTC - millisecondsUTC % (24 * 60 * 60 * 1000);
    return rounded / 1000;
  }
Returns a timestamp with only the year, month and day (with zero hours, minutes and seconds) and without 000 for milliseconds
@param { number } millisecondsUTC
@returns { number }