- /**
- * @brief General purpose date parse/convert function.
- *
- * @param string $s Some parseable date/time string
- * @param string $from Source timezone
- * @param string $to Dest timezone
- * @param string $fmt Output format recognised from php's DateTime class
- * http://www.php.net/manual/en/datetime.format.php
- *
- * @return string Formatted date according to given format
- */
- public static function convert($s = 'now', $to = 'UTC', $from = 'UTC', $fmt = "Y-m-d H:i:s")
- {
- // Defaults to UTC if nothing is set, but throws an exception if set to empty string.
- // Provide some sane defaults regardless.
- if ($from === '') {
- $from = 'UTC';
- }
-
- if ($to === '') {
- $to = 'UTC';
- }
-
- if (($s === '') || (!is_string($s))) {
- $s = 'now';
- }
-
- /*
- * Slight hackish adjustment so that 'zero' datetime actually returns what is intended
- * otherwise we end up with -0001-11-30 ...
- * add 32 days so that we at least get year 00, and then hack around the fact that
- * months and days always start with 1.
- */
-
- if (substr($s, 0, 10) <= '0001-01-01') {
- $d = new DateTime($s . ' + 32 days', new DateTimeZone('UTC'));
- return str_replace('1', '0', $d->format($fmt));
- }
-
- try {
- $from_obj = new DateTimeZone($from);
- } catch (Exception $e) {
- $from_obj = new DateTimeZone('UTC');
- }
-
- try {
- $d = new DateTime($s, $from_obj);
- } catch (Exception $e) {
- logger('datetime_convert: exception: ' . $e->getMessage());
- $d = new DateTime('now', $from_obj);
- }
-
- try {
- $to_obj = new DateTimeZone($to);
- } catch (Exception $e) {
- $to_obj = new DateTimeZone('UTC');
- }
-
- $d->setTimeZone($to_obj);
-
- return $d->format($fmt);
- }
-