I benched a few different ways:
1) microtime + sscanf + date:
sscanf(microtime(), '0.%6s00 %s', $usec, $sec);
$date = date('Y-m-d H:i:s.', $sec) . $usec;
I'm not sure why microtime() returns 10 chars (0.dddddd00) for the microseconds part but maybe someone can tell me ?
$start_ts = microtime(true); for($i = 0; $i < 10000000; $i++) { sscanf(microtime(), '0.%6s00 %s', $usec, $sec); $date = date('Y-m-d H:i:s.', $sec) . $usec; } var_dump((microtime(true) - $start_ts)*1000 . ' ms');
string(18) "22372.335910797 ms" // macOS PHP 5.6.30
string(18) "16772.964000702 ms" // Linux PHP 5.4.16
string(18) "10382.229089737 ms" // Linux PHP 7.3.11 (same linux box as above)
2) DateTime::createFromFormat + Datetime->format:
$now = new DateTime('NOW');
$date = $now->format('Y-m-d H:i:s.u');
not working in PHP 5.x ...
$start_ts = microtime(true); for($i = 0; $i < 10000000; $i++) { $now = new DateTime('NOW'); $date = $now->format('Y-m-d H:i:s.u'); } var_dump((microtime(true) - $start_ts)*1000 . ' ms');
string(18) "45801.825046539 ms" // macOS PHP 5.6.30 (ms not working)
string(18) "21180.155038834 ms" // Linux PHP 5.4.16 (ms not working)
string(18) "11879.796028137 ms" // Linux PHP 7.3.11 (same linux box as above)
3) gettimeofday + date:
$time = gettimeofday();
$date = date('Y-m-d H:i:s.', $time['sec']) . $time['usec'];
-
$start_ts = microtime(true); for($i = 0; $i < 10000000; $i++) { $time = gettimeofday(); $date = date('Y-m-d H:i:s.', $time['sec']) . $time['usec']; } var_dump((microtime(true) - $start_ts)*1000 . ' ms');
string(18) "23706.788063049 ms" // macOS PHP 5.6.30
string(18) "14984.534025192 ms" // Linux PHP 5.4.16
string(18) "7799.1390228271 ms" // Linux PHP 7.3.11 (same linux box as above)
4) microtime + number_format + DateTime::createFromFormat + DateTime->format:
$now = DateTime::createFromFormat('U.u', number_format(microtime(true), 6, '.', ''));
$date = $now->format('Y-m-d H:i:s.u');
-
$start_ts = microtime(true); for($i = 0; $i < 10000000; $i++) { $now = DateTime::createFromFormat('U.u', number_format(microtime(true), 6, '.', '')); $date = $now->format('Y-m-d H:i:s.u'); } var_dump((microtime(true) - $start_ts)*1000 . ' ms');
string(18) "83326.496124268 ms" // macOS PHP 5.6.30
string(18) "61982.603788376 ms" // Linux PHP 5.4.16
string(16) "19107.1870327 ms" // Linux PHP 7.3.11 (same linux box as above)
5) microtime + sprintf + DateTime::createFromFormat + DateTime->format:
$now = DateTime::createFromFormat('U.u', sprintf('%.6f', microtime(true)));
$date = $now->format('Y-m-d H:i:s.u');
-
$start_ts = microtime(true); for($i = 0; $i < 10000000; $i++) { $now = DateTime::createFromFormat('U.u', sprintf('%.6f', microtime(true))); $date = $now->format('Y-m-d H:i:s.u'); } var_dump((microtime(true) - $start_ts)*1000 . ' ms');
string(18) "79387.331962585 ms" // macOS PHP 5.6.30
string(18) "60734.437942505 ms" // Linux PHP 5.4.16
string(18) "18594.941139221 ms" // Linux PHP 7.3.11 (same linux box as above)