Annoto in questo articolo l’utilizzo della funzione Date() per i formati di data più comuni in PHP.

$now = date("Y-m-d H:i:s");                   // 2015-03-10 17:16:18 (MySQL DATETIME)
$now = date("Ymd");                           // 20150310
$now = date("Y/m/d");                         // 2015/03/10
$now = date("H:i:s");                         // 17:16:18
$now = date("F j, Y, g:i a");                 // March 10, 2015, 5:16 pm
$now = date("m.d.y");                         // 03.10.15
$now = date('h-i-s, j-m-y, it is w Day');     // 05-16-18, 10-03-15, 1631 1618 6 Satpm01
$now = date('\i\t \i\s \t\h\e jS \d\a\y.');   // it is the 10th day.
$now = date("D M j G:i:s T Y");               // Sat Mar 10 17:16:18 MST 2015
$now = date('H:m:s \m \i\s\ \m\o\n\t\h');     // 17:03:18 m is month