PHP Mktime() - Timestamp yesterday, last month, etc

Intro

The mktime() function returns of the UNIX timestamp of a given date, i.e. the number of seconds elapsed between 1 January 1970 and that date. 

Syntax:
mktime(hour, minute, second, month, day, year, is_dst) 

Parameter

Name	Description	Required/ Optional	Type
hour	Numeric representation of hours	Optional	Integer
minute	Numeric representation of minute	Optional	Integer
second	Numeric representation of second	Optional	Integer
month	Numeric representation of month	Optional	Integer
day	Numeric representation of day	Optional	Integer
year	Numeric representation of year	Optional	Integer
is_dst	Whether Daylight Saving Time is active (values 1 or 0 ). In PHP 5.1.0, this parameter became deprecated. As a result, the new timezone handling features should be used instead.	Optional	Integer

Return value

The Unix timestamp corresponding to the parameters given. If the parameters are invalid, the function returns FALSE.

Value Type : Integer.

Example :

view plainprint?

1. <?php  
2. echo(date("M-d-Y",mktime(0,0,0,2,12,98))."<br />");  
3. echo(date("M-d-Y",mktime(0,0,0,17,4,2005))."<br />");  
4. echo(date("M-d-Y",mktime(0,0,0,1,36,2000))."<br />");  
5. echo(date("M-d-Y",mktime(24,0,0,1,1,99))."<br />");  
6. ?>  

Output :

Feb-12-1998
May-04-2006
Feb-05-2000
Jan-02-1999

- See more at: http://www.w3resource.com/php/function-reference/mktime.php#sthash.1FAVbWEq.dpuf

Note: To convert the timestamps below to a format suitable for use with MySQL, use the date function as follows: 

<?     
$mysql_datetime = date('Y-m-d H:i:s',$timestamp);     
?>

Below are the mostly used examples: 

Last 24 hours

The code below covers the past 24 hours so far: 

<?php     
$startTime = mktime() - 24*3600;     
$endTime = mktime();     
?>

Yesterday

The code below works even if you are the 1st of the month or the 1st January of the year. It covers the period from yesterday at 00:00:00 to 23:59:59 yesterday: 

<?php     
$startTime = mktime(0, 0, 0, date('m'), date('d')-1, date('Y'));     
$endTime = mktime(23, 59, 59, date('m'), date('d')-1, date('Y'));     
?>

This week

The code below assumes that the first day of the week is Monday. It covers the period from Monday morning at 00:00:00 to now: 

<?     
$startTime = mktime(0, 0, 0, date('n'), date('j'), date('Y')) - ((date('N')-1)*3600*24);     
$endTime = mktime();      
?>

Last week

The code below assumed that the first day of the week is Monday. It covers the period from the Monday before last at 00:00:00 to the following Sunday at 23:59:59: 

<?     
$startTime = mktime(0, 0, 0, date('n'), date('j')-6, date('Y')) - ((date('N'))*3600*24);     
$endTime = mktime(23, 59, 59, date('n'), date('j'), date('Y')) - ((date('N'))*3600*24);     
?>

This Month

The code below covers the period from the first of the current to now: 

<?     
$startTime = mktime(0, 0, 0, date('m'), 1, date('Y'));     
$endTime = mktime();     
?>

Last 30 days

The code below covers the period from 30 days ago to now: 

<?      
$ starttime = mktime () - 30 * 3600 * 24;      
$ endTime = mktime ();      
> 

Last month

The code below covers the previous month: 

<?     
$startTime = mktime() - 30*3600*24;     
$endTime = mktime();     
?> 

Current year

The code below covers the period from January 1st to 00:00:00 today: 

<?     
$startTime = mktime(0, 0, 0, 1, 1, date('Y'));     
$endTime = mktime();     
?>

Last year

The code below covers the previous year, from January 1, at 00:00:00 to 31 December at 23:59:59: 

<?     
$startTime = mktime(0, 0, 0, 1, 1, date('Y')-1);     
$endTime = mktime(23, 59, 59, 12, 31, date('Y')-1);     
?>