code: static DateValue nextWeekStart(DateValue date, DayOfWeek weekday) {
  		DTBuilder builder = new DTBuilder(date);
  		builder.day += (7 - ((7 + (TimeUtils.dayOfWeek(date).getCalendarConstant() - weekday.getCalendarConstant())) % 7)) % 7;
  		return builder.toDate();
  	}
docs: <p>
  Advances the given date to next date that falls on the given weekday. If
  the given date already falls on the given weekday, then the same date is
  returned.
  </p>
  <p>
  For example, if the date is a Thursday, and the week start is Monday,
  this method will return a date value that is set to the next Monday (4
  days in the future).
  </p>
  @param date the date
  @param weekday the day of the week that the week starts on
  @return the resultant date