public static function addDateUnitToTimestamp($timestamp, $units, $unitType, $returnDate = true)
{
$d = $timestamp;
switch ($unitType) {
case Gpf_Common_DateUtils::DAY:
if (self::belowMinTimestamp($timestamp + Gpf_DateTime::daysToSeconds($units))) {
$time = Gpf_DateTime::MIN_TIMESTAMP;
break;
}
if (self::overMaxTimestamp($timestamp + Gpf_DateTime::daysToSeconds($units))) {
$time = Gpf_DateTime::MAX_TIMESTAMP;
break;
}
$time = mktime(0, 0, 0, date("m", $d), date("d", $d) + $units, date("Y", $d));
break;
case Gpf_Common_DateUtils::WEEK:
if (self::belowMinTimestamp($timestamp + Gpf_DateTime::weeksToSeconds($units))) {
$time = Gpf_DateTime::MIN_TIMESTAMP;
break;
}
if (self::overMaxTimestamp($timestamp + Gpf_DateTime::weeksToSeconds($units))) {
$time = Gpf_DateTime::MAX_TIMESTAMP;
break;
}
$time = mktime(0, 0, 0, date("m", $d), date("d", $d) + 7 * $units, date("Y", $d));
break;
case Gpf_Common_DateUtils::MONTH:
if (self::belowMinTimestamp($timestamp + Gpf_DateTime::monthsToSeconds($units))) {
$time = Gpf_DateTime::MIN_TIMESTAMP;
break;
}
if (self::overMaxTimestamp($timestamp + Gpf_DateTime::monthsToSeconds($units))) {
$time = Gpf_DateTime::MAX_TIMESTAMP;
break;
}
$month = date("m", $d) + $units;
$day = self::daysInMonth($month, date("d", $d), date("Y", $d));
$time = mktime(0, 0, 0, $month, $day, date("Y", $d));
break;
case Gpf_Common_DateUtils::YEAR:
if (self::belowMinTimestamp($timestamp + Gpf_DateTime::yearsToSeconds($units))) {
$time = Gpf_DateTime::MIN_TIMESTAMP;
break;
}
if (self::overMaxTimestamp($timestamp + Gpf_DateTime::yearsToSeconds($units))) {
$time = Gpf_DateTime::MAX_TIMESTAMP;
break;
}
$time = mktime(0, 0, 0, date("m", $d), date("d", $d), date("Y", $d) + $units);
break;
}
if ($returnDate) {
return Gpf_Common_DateUtils::getDate($time);
}
return Gpf_Common_DateUtils::getDateTime($time);
}