how to get number of days in the month with php

if you want to know number of days in the month with php, you can call function cal_days_in_month()
this function returns the number of days in a given month, based on the calendar, month, and year that you specify

the format of this function is
Cal_days_in_month (calendar, Month, year)
This function have three parameters,

• calendar, you can fill this parameter with CAL_GREGORIAN
  
• month, you can fill this parameter with month (1 - 12)
  
• year, you can fiil this parameter with 4 digits of year (2008)

example :
$days = cal_days_in_month(CAL_GREGORIAN, 1, 2009) ;
echo "In January 2009 there were $days days";
?>

that example will display
In january 2009 there were 31 days

Date Function on PHP

to display the time and date in PHP, we can use date function. This function have several parameter. example

<?
date('d-m-y h:i:s')
?>
this syntax will return 21-05-2007 15:25:32.
For other parameters, please try to change the example above.

format character	Description	Example returned values
a	Lowercase Ante meridiem and Post meridiem	am or pm
A	Uppercase Ante meridiem and Post meridiem	AM or PM
B	Swatch Internet time	000 through 999
d	Day of the month, 2 digits with leading zeros	01 to 31
D	A textual representation of a day, three letters	Mon through Sun
F	A full textual representation of a month, such as January or March	January through December
g	12-hour format of an hour without leading zeros	1 through 12
G	24-hour format of an hour without leading zeros	0 through 23
h	12-hour format of an hour with leading zeros	01 through 12
H	24-hour format of an hour with leading zeros	00 through 23
i	Minutes with leading zeros	00 to 59
I (capital i)	Whether or not the date is in daylights savings time	1 if Daylight Savings Time, 0 otherwise.
j	Day of the month without leading zeros	1 to 31
l (lowercase 'L')	A full textual representation of the day of the week	Sunday through Saturday
L	Whether it's a leap year	1 if it is a leap year, 0 otherwise.
m	Numeric representation of a month, with leading zeros	01 through 12
M	A short textual representation of a month, three letters	Jan through Dec
n	Numeric representation of a month, without leading zeros	1 through 12
O	Difference to Greenwich time (GMT) in hours	Example: +0200
r	RFC 822 formatted date	Example: Thu, 21 Dec 2000 16:01:07 +0200
s	Seconds, with leading zeros	00 through 59
S	English ordinal suffix for the day of the month, 2 characters	st, nd, rd or th. Works well with j
t	Number of days in the given month	28 through 31
T	Timezone setting of this machine	Examples: EST, MDT ...
U	Seconds since the Unix Epoch (January 1 1970 00:00:00 GMT)	See also time()
w	Numeric representation of the day of the week	0 (for Sunday) through 6 (for Saturday)
W	ISO-8601 week number of year, weeks starting on Monday (added in PHP 4.1.0)	Example: 42 (the 42nd week in the year)
Y	A full numeric representation of a year, 4 digits	Examples: 1999 or 2003
y	A two digit representation of a year	Examples: 99 or 03
z	The day of the year	0 through 366
Z	Timezone offset in seconds. The offset for timezones west of UTC is always negative, and for those east of UTC is always positive.	-43200 through 43200