public static long subDays(final Date date1, final Date date2) {

    return subTime(date1, date2, DatePeriod.DAY);
  }
public static long subDays ( final Date date1 , final Date date2 ) { return subTime ( date1 , date2 , DatePeriod . DAY ) ; }
Get how many days between two date.

@param date1 date to be tested.
@param date2 date to be tested.
@return how many days between two date.