build/ical.js
function icaltime_subtract_abs(aDate) {
      var unixTime = this.toUnixTime();
      var other = aDate.toUnixTime();
      return ICAL.Duration.fromSeconds(unixTime - other);
    }
function icaltime_subtract_abs(aDate) {
      var unixTime = this.toUnixTime();
      var other = aDate.toUnixTime();
      return ICAL.Duration.fromSeconds(unixTime - other);
    }
function icaltime_subtract_abs ( aDate ) { var unixTime = this . toUnixTime ( ) ; var other = aDate . toUnixTime ( ) ; return ICAL . Duration . fromSeconds ( unixTime - other ) ; }
Subtract the date details, taking timezones into account.

@param {ICAL.Time} aDate  The date to subtract
@return {ICAL.Duration}  The difference in duration
Subtract the date details taking timezones into account .