/**
* Returns the time zone raw and GMT offset for the given moment
* in time. Upon return, local-millis = GMT-millis + rawOffset +
* dstOffset. All computations are performed in the proleptic
* Gregorian calendar. The default implementation in the TimeZone
* class delegates to the 8-argument getOffset().
*
* @param float Moment in time for which to return offsets, in units of
* milliseconds from January 1, 1970 0:00 GMT, either GMT
* time or local wall time, depending on `local'.
* @param bool If true, `date' is local wall time; otherwise it
* is in GMT time.
* @param int Output parameter to receive the raw offset, that is, the
* offset not including DST adjustments
* @param int Output parameter to receive the DST offset, that is, the
* offset to be added to `rawOffset' to obtain the total
* offset between local and GMT time. If DST is not in
* effect, this value is zero; otherwise it is a positive
* value, typically one hour.
*
* @author Dominik del Bondio <*****@*****.**>
* @author The ICU Project
* @since 0.11.0
*/
public function getOffsetRef($date, $local, &$rawOffset, &$dstOffset)
{
$rawOffset = $this->getRawOffset();
// Convert to local wall millis if necessary
if (!$local) {
$date += $rawOffset;
// now in local standard millis
}
// When local==FALSE, we might have to recompute. This loop is
// executed once, unless a recomputation is required; then it is
// executed twice.
for ($pass = 0; true; ++$pass) {
$year = $month = $dom = $dow = 0;
$day = floor($date / AgaviDateDefinitions::MILLIS_PER_DAY);
$millis = (int) ($date - $day * AgaviDateDefinitions::MILLIS_PER_DAY);
AgaviCalendarGrego::dayToFields($day, $year, $month, $dom, $dow);
$dstOffset = $this->getOffsetIIIIIII(AgaviGregorianCalendar::AD, $year, $month, $dom, $dow, $millis, AgaviCalendarGrego::monthLength($year, $month)) - $rawOffset;
// Recompute if local==FALSE, dstOffset!=0, and addition of
// the dstOffset puts us in a different day.
if ($pass != 0 || $local || $dstOffset == 0) {
break;
}
$date += $dstOffset;
if (floor($date / AgaviDateDefinitions::MILLIS_PER_DAY) == $day) {
break;
}
}
}
/**
* AgaviTimeZone API.
*
* @see AgaviTimeZone::useDaylightTime()
*
* @author Dominik del Bondio <*****@*****.**>
* @author The ICU Project
* @since 0.11.0
*/
public function useDaylightTime()
{
// If DST was observed in 1942 (for example) but has never been
// observed from 1943 to the present, most clients will expect
// this method to return FALSE. This method determines whether
// DST is in use in the current year (at any point in the year)
// and returns TRUE if so.
$days = floor(AgaviCalendar::getNow() / AgaviDateDefinitions::MILLIS_PER_DAY);
// epoch days
$year = 0;
$month = 0;
$dom = 0;
$dow = 0;
AgaviCalendarGrego::dayToFields($days, $year, $month, $dom, $dow);
if ($year > $this->finalYear) {
// [sic] >, not >=; see above
if ($this->finalZone) {
return $this->finalZone->useDaylightTime();
} else {
return true;
}
}
// Find start of this year, and start of next year
$start = (int) AgaviCalendarGrego::fieldsToDay($year, 0, 1) * AgaviDateDefinitions::SECONDS_PER_DAY;
$limit = (int) AgaviCalendarGrego::fieldsToDay($year + 1, 0, 1) * AgaviDateDefinitions::SECONDS_PER_DAY;
// Return TRUE if DST is observed at any time during the current year.
for ($i = 0, $transitionCount = count($this->transitions); $i < $transitionCount; ++$i) {
if ($this->transitions[$i]['time'] >= $limit) {
break;
}
if ($this->transitions[$i]['time'] >= $start && $this->types[$this->transitions[$i]['type']]['dstOffset'] != 0 || $this->transitions[$i]['time'] > $start && $i > 0 && $this->types[$this->transitions[$i - 1]['type']]['dstOffset'] != 0) {
return true;
}
}
return false;
}
/**
* Compute the Gregorian calendar year, month, and day of month from the
* Julian day. These values are not stored in fields, but in member
* variables gregorianXxx. They are used for time zone computations and by
* subclasses that are Gregorian derivatives. Subclasses may call this
* method to perform a Gregorian calendar millis->fields computation.
* To perform a Gregorian calendar fields->millis computation, call
* computeGregorianMonthStart().
* @see #computeGregorianMonthStart
*
* @param int The julian day
*
* @author Dominik del Bondio <*****@*****.**>
* @author The ICU Project
* @since 0.11.0
*/
private function computeGregorianFields($julianDay)
{
$gregorianDayOfWeekUnused = 0;
AgaviCalendarGrego::dayToFields($julianDay - AgaviDateDefinitions::EPOCH_START_AS_JULIAN_DAY, $this->fGregorianYear, $this->fGregorianMonth, $this->fGregorianDayOfMonth, $gregorianDayOfWeekUnused, $this->fGregorianDayOfYear);
}
