(PHP 5.5.0, PECL >= 3.0.0a1)
IntlCalendar::before — Whether this objectʼs time is before that of the passed object
Returns whether this objectʼs time precedes the argumentʼs time.
calendar
    The calendar whose time will be checked against this objectʼs time.
   Returns TRUE if this objectʼs current time is before that of the
   calendar argumentʼs time. Returns FALSE otherwise.
   Also returns FALSE on failure. You can use exceptions or
    intl_get_error_code() to detect error conditions.