Date Format in PHP for date month year and time

We can apply date format on date objects returned by or created from DateTime function or any other way . Here are some example of displaying date and time by using format.

date_default_timezone_set('America/Chicago');
$date = new DateTime('2012-04-15 22:15:40');
echo $date->format('Y/m/d H:i:s');

The output is here

2012/04/15 22:15:40

Examples:

echo date('t'); //will return number of days in current month
echo date('Y'); //will return Year in four digits: 2013

Characters used for formating string in PHP date format

a	'am' or 'pm'
A	'AM' or 'PM'
B	Swatch Internet time
d	day of the month, 2 digits with leading zeros; i.e. '01' to '31'
D	day of the week, textual, 3 letters; i.e. 'Fri'
F	month, textual, long; i.e. 'January'
g	hour, 12-hour format without leading zeros; i.e. '1' to '12'
G	hour, 24-hour format without leading zeros; i.e. '0' to '23'
h	hour, 12-hour format; i.e. '01' to '12'
H	hour, 24-hour format; i.e. '00' to '23'
i	minutes; i.e. '00' to '59'
I (capital i)	'1' if Daylight Savings Time, '0' otherwise.
j	day of the month without leading zeros; i.e. '1' to '31'
l (lowercase 'L')	day of the week, textual, long; i.e. 'Friday'
L	boolean for whether it is a leap year; i.e. '0' or '1'
m	month; i.e. '01' to '12'
M	month, textual, 3 letters; i.e. 'Jan'
n	month without leading zeros; i.e. '1' to '12'
r	RFC 822 formatted date; i.e. 'Thu, 21 Dec 2000 16:01:07 +0200' (added in PHP 4.0.4)
s	seconds; i.e. '00' to '59'
S	English ordinal suffix, textual, 2 characters; i.e. 'th', 'nd'
t	number of days in the given month; i.e. '28' to '31'
T	Timezone setting of this machine; i.e. 'MDT'
U	seconds since the epoch
w	day of the week, numeric, i.e. '0' (Sunday) to '6' (Saturday)
Y	year, 4 digits; i.e. '1999'
y	year, 2 digits; i.e. '99'
z	day of the year; i.e. '0' to '365'
Z	timezone offset in seconds (i.e. '-43200' to '43200'). The offset for timezones west of UTC is always negative, and for those east of UTC is always positive.
You can use the above date format for formating php today date and displaying php date and time in different ways.