Here's a simple reference of the datetime vars that you can use:

Year Data:
	Y:       /* Y - year, 4 digits; e.g. "1999" */
	y:       /* y - year, 2 digits; e.g. "99" */
	L:       /* L - boolean for whether it is a leap year; i.e. "0" or "1" */

Month Data:
	F:       /* F - month, textual, long; e.g. "January" */
	m:       /* m - month; i.e. "01" to "12" */
	M:       /* M - month, textual, 3 letters; e.g. "Jan" */
	n:       /* n - month without leading zeros; i.e. "1" to "12" */
	t:       /* t - number of days in the given month; i.e. "28" to "31" */

Day Data:
	d:       /* d - day of the month, 2 digits with leading zeros; i.e. "01" to "31" */
	j:       /* j - day of the month without leading zeros; i.e. "1" to "31" */
	S:       /* S - English ordinal suffix for the day of the month, 2 characters; i.e. "st", "nd", "rd" or "th" */
	D:       /* D - day of the week, textual, 3 letters; e.g. "Fri" */
	l:       /* l - day of the week, textual, e.g. "Friday" */
	w:       /* w - day of the week, numeric, i.e. "0" (Sunday) to "6" (Saturday) */
	z:       /* z - day of the year; i.e. "0" to "365" */

Time Data:
	g:       /* g - hour, 12-hour format without leading zeros; i.e. "1" to "12" */
	G:       /* G - hour, 24-hour format without leading zeros; i.e. "0" to "23" */
	h:       /* h - hour, 12-hour format; i.e. "01" to "12" */
	H:       /* H - hour, 24-hour format; i.e. "00" to "23" */
	i:       /* i - minutes; i.e. "00" to "59" */
	s:       /* s - seconds; i.e. "00" to "59" */
	a:       /* a - "am" or "pm" */
	A:       /* A - "AM" or "PM" */


Miscellaneous:
	B:       /* B - Swatch Internet time */
	I:       /* I (capital i) - "1" if Daylight Savings Time, "0" otherwise. */
	O:       /* O - Difference to Greenwich time in hours; e.g. "+0200" */
	R:       /* r - RFC 822 formatted date; e.g. "Thu, 21 Dec 2000 16:01:07 +0200" */
	T:       /* T - Timezone setting of this machine; e.g. "EST" or "MDT" */
	U:       /* U - seconds since the Unix Epoch (January 1 1970 00:00:00 GMT) */
	W:       /* W - ISO-8601 week number of year, weeks starting on Monday */
	Z:       /* Z - timezone offset in seconds (i.e. "-43200" to "43200").
