PHP 5.6.0 released

mktime

(PHP 4, PHP 5)

mktimeGet Unix timestamp for a date

Description

int mktime ([ int $hour = date("H") [, int $minute = date("i") [, int $second = date("s") [, int $month = date("n") [, int $day = date("j") [, int $year = date("Y") [, int $is_dst = -1 ]]]]]]] )

Returns the Unix timestamp corresponding to the arguments given. This timestamp is a long integer containing the number of seconds between the Unix Epoch (January 1 1970 00:00:00 GMT) and the time specified.

Arguments may be left out in order from right to left; any arguments thus omitted will be set to the current value according to the local date and time.

Notes

Note:

As of PHP 5.1, when called with no arguments, mktime() throws an E_STRICT notice: use the time() function instead.

Parameters

hour

The number of the hour relative to the start of the day determined by month, day and year. Negative values reference the hour before midnight of the day in question. Values greater than 23 reference the appropriate hour in the following day(s).

minute

The number of the minute relative to the start of the hour. Negative values reference the minute in the previous hour. Values greater than 59 reference the appropriate minute in the following hour(s).

second

The number of seconds relative to the start of the minute. Negative values reference the second in the previous minute. Values greater than 59 reference the appropriate second in the following minute(s).

month

The number of the month relative to the end of the previous year. Values 1 to 12 reference the normal calendar months of the year in question. Values less than 1 (including negative values) reference the months in the previous year in reverse order, so 0 is December, -1 is November, etc. Values greater than 12 reference the appropriate month in the following year(s).

day

The number of the day relative to the end of the previous month. Values 1 to 28, 29, 30 or 31 (depending upon the month) reference the normal days in the relevant month. Values less than 1 (including negative values) reference the days in the previous month, so 0 is the last day of the previous month, -1 is the day before that, etc. Values greater than the number of days in the relevant month reference the appropriate day in the following month(s).

year

The number of the year, may be a two or four digit value, with values between 0-69 mapping to 2000-2069 and 70-100 to 1970-2000. On systems where time_t is a 32bit signed integer, as most common today, the valid range for year is somewhere between 1901 and 2038. However, before PHP 5.1.0 this range was limited from 1970 to 2038 on some systems (e.g. Windows).

is_dst

This parameter can be set to 1 if the time is during daylight savings time (DST), 0 if it is not, or -1 (the default) if it is unknown whether the time is within daylight savings time or not. If it's unknown, PHP tries to figure it out itself. This can cause unexpected (but not incorrect) results. Some times are invalid if DST is enabled on the system PHP is running on or is_dst is set to 1. If DST is enabled in e.g. 2:00, all times between 2:00 and 3:00 are invalid and mktime() returns an undefined (usually negative) value. Some systems (e.g. Solaris 8) enable DST at midnight so time 0:30 of the day when DST is enabled is evaluated as 23:30 of the previous day.

Note:

As of PHP 5.1.0, this parameter became deprecated. As a result, the new timezone handling features should be used instead.

Return Values

mktime() returns the Unix timestamp of the arguments given. If the arguments are invalid, the function returns FALSE (before PHP 5.1 it returned -1).

Errors/Exceptions

Every call to a date/time function will generate a E_NOTICE if the time zone is not valid, and/or a E_STRICT or E_WARNING message if using the system settings or the TZ environment variable. See also date_default_timezone_set()

Changelog

Version Description
5.3.0 mktime() now throws E_DEPRECATED notice if the is_dst parameter is used.
5.1.0 The is_dst parameter became deprecated. Made the function return FALSE on error, instead of -1. Fixed the function to accept the year, month and day to be all passed as zero.
5.1.0 When called with no arguments, mktime() throws E_STRICT notice. Use the time() function instead.
5.1.0

Now issues the E_STRICT and E_NOTICE time zone errors.

Examples

Example #1 mktime() basic example

<?php
// Set the default timezone to use. Available as of PHP 5.1
date_default_timezone_set('UTC');

// Prints: July 1, 2000 is on a Saturday
echo "July 1, 2000 is on a " date("l"mktime(000712000));

// Prints something like: 2006-04-05T01:02:03+00:00
echo date('c'mktime(123452006));
?>

Example #2 mktime() example

mktime() is useful for doing date arithmetic and validation, as it will automatically calculate the correct value for out-of-range input. For example, each of the following lines produces the string "Jan-01-1998".

<?php
echo date("M-d-Y"mktime(00012321997));
echo 
date("M-d-Y"mktime(0001311997));
echo 
date("M-d-Y"mktime(000111998));
echo 
date("M-d-Y"mktime(0001198));
?>

Example #3 Last day of a month

The last day of any given month can be expressed as the "0" day of the next month, not the -1 day. Both of the following examples will produce the string "The last day in Feb 2000 is: 29".

<?php
$lastday 
mktime(000302000);
echo 
strftime("Last day in Feb 2000 is: %d"$lastday);
$lastday mktime(0004, -312000);
echo 
strftime("Last day in Feb 2000 is: %d"$lastday);
?>

Notes

Caution

Before PHP 5.1.0, negative timestamps were not supported under any known version of Windows and some other systems as well. Therefore the range of valid years was limited to 1970 through 2038.

See Also

add a note add a note

User Contributed Notes 21 notes

up
9
Alan
5 years ago
Do remember that, counter-intuitively enough, the arguments for month and day are inversed (or middle-endian). A common mistake for Europeans seems to be to feed the date arguments in the expected order (big endian or little endian).

It's clear to see where this weird order comes from (even with the date being big endian the order for all arguments would still be mixed - it's obviously based on the American date format with the time "prefixed" to allow an easier shorthand) and why this wasn't changed (passing the values in the wrong order produces a valid, though unexpected, result in most cases), but it continues to be a source of confusion for me whenever I come back to PHP from other languages or libraries.
up
6
joseph dot andrew dot hughes at gmail dot com
6 years ago
Just a small thing to think about if you are only trying to pull the month out using mktime and date.  Make sure you place a 1 into day field.  Otherwise you will get incorrect dates when a month is followed by a month with less days when the day of the current month is higher then the max day of the month you are trying to find.. (Such as today being Jan 30th and trying to find the month Feb.)
up
3
info at microweb dot lt
3 years ago
Function to generate array of dates between two dates (date range array)

<?php
function dates_range($date1, $date2)
{
   if (
$date1<$date2)
   {
      
$dates_range[]=$date1;
      
$date1=strtotime($date1);
      
$date2=strtotime($date2);
       while (
$date1!=$date2)
       {
          
$date1=mktime(0, 0, 0, date("m", $date1), date("d", $date1)+1, date("Y", $date1));
          
$dates_range[]=date('Y-m-d', $date1);
       }
   }
   return
$dates_range;
}

echo
'<pre>';
print_r(dates_range('2009-12-25', '2010-01-05'));
echo
'</pre>';
?>

[EDIT BY danbrown AT php DOT net: Contains a bugfix submitted by (carlosbuz2 AT gmail DOT com) on 04-MAR-2011, with the following note: The first date in array is incorrect.]
up
3
tom at chegg dot com
4 years ago
I was using the following to get a list of month names.

for ($i=1; $i<13; $i++) {
  echo date('F', mktime(0,0,0,$i) . ",";
}

Normally this outputs -
January,February,March,April,May,June,July,August,
September,October,November,December

However if today's date is the 31st you get instead:
January,March,March,May,May,July,July,August,October,
October,December,December

Why? Because Feb,Apr,June,Sept, and Nov don't have 31 days!

The fix, add the 5th parameter, don't let the day of month default to today's date:

  echo date('F', mktime(0,0,0,$i,1) . ",";
up
2
thomas_corthals at hotmail dot com
6 years ago
It seems mktime() doesn't return negative timestamps on Linux systems with a version of glibc <= 2.3.3.
up
0
Rad
5 months ago
Be careful passing zeros into mktime, in most cases a zero will count as the previous unit of time. The documentation explains this yet most of the comments here still use zeroes.

For example, if you pass the year 2013 into mktime, with zeroes for everything else, the outcome is probably not what you are looking for.

<?php
echo date('F jS, Y g:i:s a', mktime(0, 0, 0, 0, 0, 2013));
// November 30th, 2012 12:00:00 am
?>

Instead of using 0's, try 1's. This makes more sense (except for minutes/seconds). Maybe not as obvious of a purpose as zeroes to other programmers, though.

<?php
echo date('F jS, Y g:i:s a', mktime(1, 1, 1, 1, 1, 2013));
// January 1st, 2013 1:01:01 am
?>
up
0
ronnie dot kurniawan at gmail dot com
5 years ago
Add (and subtract) unixtime:

<?php
function utime_add($unixtime, $hr=0, $min=0, $sec=0, $mon=0, $day=0, $yr=0) {
 
$dt = localtime($unixtime, true);
 
$unixnewtime = mktime(
     
$dt['tm_hour']+$hr, $dt['tm_min']+$min, $dt['tm_sec']+$sec,
     
$dt['tm_mon']+1+$mon, $dt['tm_mday']+$day, $dt['tm_year']+1900+$yr);
  return
$unixnewtime;
}
?>
up
-1
zfowler at unomaha dot edu
4 years ago
Proper way to convert Excel dates into PHP-friendly timestamps using mktime():

<?php
// The date 6/30/2009 is stored as 39994 in Excel
$days = 39994;

// But you must subtract 1 to get the correct timestamp
$ts = mktime(0,0,0,1,$days-1,1900);

// So, this would then match Excel's representation:
echo date("m/d/Y",$ts);
?>

Excel uses "number of days since Jan. 1, 1900" to store its dates.  It also treats 1900 as a leap year when it wasn't, thus there is an extra day which must be accounted for in PHP (and the rest of the world).  Subtracting 1 from Excel's number will fix this problem.
up
-1
ionut dot bodea at eydos dot ro
5 years ago
Here is what I use to calculate age. It took me 30 minutes to write and it's quite accurate. What it has special is that it's calculating the number of days a year has (float number), by testing if a year is a leap one or not. This number is used to compute the age.

<?php
function get_age($date_start, $date_end) {
   
$t_lived = get_timestamp($date_end) - get_timestamp($date_start);
   
$seconds_one_year = get_days_per_year($date_start, $date_end) * 24 * 60 * 60;
   
$age = array();
   
$age['years_exact'] = $t_lived / $seconds_one_year;
   
$age['years'] = floor($t_lived / $seconds_one_year);
   
$seconds_remaining = $t_lived % $seconds_one_year;
   
$age['days'] = round($seconds_remaining / (24 * 60 * 60));
    return
$age;
}
function
get_timestamp($date) {
    list(
$y, $m, $d) = explode('-', $date);
    return
mktime(0, 0, 0, $m, $d, $y);
}
function
get_days_per_year($date_start, $date_end) {
    list(
$y1) = explode('-', $date_start);
    list(
$y2) = explode('-', $date_end);
   
$years_days = array();
    for(
$y = $y1; $y <= $y2; $y++) {
       
$years_days[] = date('L', mktime(0, 0, 0, 1, 1, $y)) ? 366 : 365;
    }
    return
round(array_sum($years_days) / count($years_days), 2);
}

$date_birth = '1979-10-12';
$date_now = date('Y-m-d');

$age = get_age($date_birth, $date_now);
echo
'<pre>';
print_r($age);
echo
'</pre>';
?>


It will display something like this:
Array
(
    [years_exact] => 28.972974329491
    [years] => 28
    [days] => 355
)
up
-1
info at djdb dot be
11 months ago
raw date to clean timestamp
private function dateToTimestamp($date){
        $datefrom = explode(" ", $date);
        $value = array();
        if(strpos($datefrom[0], '-')){
            //print "issplit -";
            $value = explode("-", $datefrom[0]);
        }
        if(strpos($datefrom[0], '/')){
            //print "issplit /";
            $value = explode("/", $datefrom[0]);
        }
        /*if(){
           
        }*/
        if(strlen($value[2])==4){//13/12/2012
            //int mktime([hour[minute[second[month[day[year
            return mktime(0, 0, 0,$value[1],$value[0],$value[2]);
        }else{                  //2012/12/13
            //int mktime([hour[minute[second[month[day[year
            return mktime(0, 0, 0,$value[1],$value[2],$value[0]);
        }
    }
up
-1
ooogla at hotmail dot com
6 years ago
If you want to increment the day based on a variable when using a loop you can use this when you submit a form

1. Establish a start date and end date in two different variables

2. Get the number of days between a date

$ndays = (strtotime($_POST['edate']) - strtotime($_POST['sdate'])) / (60 * 60 * 24);

Then here is the string you slip in your loop

$nextday  = date('Y-m-d', mktime(0, 0, 0, date("m", strtotime($_POST['sdate']))  , date("d", strtotime($_POST['sdate']))+ $count, date("Y", strtotime($_POST['sdate']))));

$count is incremented by the loop.
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-1
PHPcoder at freemail dot ig3 dot net
6 years ago
The maximum possible date accepted by mktime() and gmmktime() is dependent on the current location time zone.

For example, the 32-bit timestamp overflow occurs at 2038-01-19T03:14:08+0000Z.  But if you're in a UTC -0500 time zone (such as EST in North America), the maximum accepted time before overflow (for older PHP versions on Windows) is 2038-01-18T22:14:07-0500Z, regardless of whether you're passing it to mktime() or gmmktime().
up
-2
rga at merchantpal dot com
7 years ago
You cannot simply subtract or add month VARs using mktime to obtain previous or next months as suggested in previous user comments (at least not with a DD > 28 anyway).

If the date is 03-31-2007, the following yeilds March as a previous month. Not what you wanted.

<?php
$dateMinusOneMonth
= mktime(0, 0, 0, (3-1), 312007 );
$lastmonth = date("n | F", $dateMinusOneMonth);
echo
$lastmonth;    //---> 3 | March
?>

mktime correctly gives you back the 3rd of March if you subtract 1 month from March 31 (there are only 28 days in Feb 07).

If you are just looking to do month and year arithmetic using mktime, you can use general days like 1 or 28 to do stuff like this:

<?php
$d_daysinmonth
= date('t', mktime(0,0,0,$myMonth,1,$myYear));     // how many days in month
$d_year = date('Y', mktime(0,0,0,$myMonth,1,$myYear));        // year
$d_isleapyear = date('L', mktime(0,0,0,$myMonth,1,$myYear));    // is YYYY a leapyear?

$d_firstdow = date('w', mktime(0,0,0,$myMonth,'1',$myYear));     // FIRST falls on what day of week (0-6)
$d_firstname = date('l', mktime(0,0,0,$myMonth,'1',$myYear));     // FIRST falls on what day of week Full Name

$d_month = date('n', mktime(0,0,0,$myMonth,28,$myYear));         // month of year (1-12)
$d_monthname = date('F', mktime(0,0,0,$myMonth,28,$myYear));         // Month Long name (July)
$d_month_previous = date('n', mktime(0,0,0,($myMonth-1),28,$myYear));         // PREVIOUS month of year (1-12)
$d_monthname_previous = date('F', mktime(0,0,0,($myMonth-1),28,$myYear));     // PREVIOUS Month Long name (July)
$d_month_next = date('n', mktime(0,0,0,($myMonth+1),28,$myYear));         // NEXT month of year (1-12)
$d_monthname_next = date('F', mktime(0,0,0,($myMonth+1),28,$myYear));         // NEXT Month Long name (July)
$d_year_previous = date('Y', mktime(0,0,0,$myMonth,28,($myYear-1)));        // PREVIOUS year
$d_year_next = date('Y', mktime(0,0,0,$myMonth,28,($myYear+1)));        // NEXT year

$d_weeksleft = (52 - $d_weekofyear);                     // how many weeks left in year
$d_daysinyear = $d_isleapyear ? 366 : 365;                // set correct days in year for leap years
$d_daysleft = ($d_daysinyear - $d_dayofyear);                // how many days left in year
?>
up
-3
Stephen
7 years ago
There are several warnings here about using mktime() to determine a date difference because of daylight savings time. However, nobody seems to have mentioned the other obvious problem, which is leap years.

Leap years mean that any effort to use mktime() and time() to determine the age (positive or negative) of some timestamp in years will be flawed. There are some years that are 366 days long, therefore you cannot say that there is a set number of seconds per year.

Timestamps are good for determining *real* time, which is not the same thing as *human calendar* time. The Gregorian calendar is only an approximation of real time, which is tweaked with daylight savings time and leap years to make it conform more to humans' expectations of how time should or ought to work. Timestamps are not tweaked and therefore are the only authoritative way of recording in computers a proper order of succession of events, but they cannot be integrated with a Gregorian system unless you take both leap years and DST into account. Otherwise, you may get the wrong number of years when you are approaching a value of exactly X years.

As for PHP, you could still use timestamps as a way of determining age if you took into account not only DST but also whether or not each year is a leap year and adjusted your calculations accordingly. However, this could become messy and inefficient.

There is an alternative approach to calculating days given the day, month and year of the dates to be compared. Compare the years first, and then compare the month and day - if the month and day have already passed (or, if you like, if they match the current month and day), then add 1 to the total for the years.

This solution works because it stays within the Gregorian system and doesn't venture into the world of timestamps.

There is also the issue of leap seconds, but this will only arise if you literally need to get the *exact* age in seconds. In that case, of course, you would also need to verify that your timestamps are exactly correct and are not delayed by script processing time, plus you would need to determine whether your system conforms to UTC, etc. I expect this will hardly be an issue for anybody using PHP, however if you are interested there is an article on this issue on Wikipedia:

http://en.wikipedia.org/wiki/Leap_second
up
-4
cebleo at n-trance dot net
4 years ago
to ADD or SUBSTRACT times NOTE that if you dont specify the UTC zone your result is the difference +- your server UTC delay.

if you are ina utc/GMT +1

<?php
$hours_diff
= strtotime("20:00:00")-strtotime("19:00:00");
echo 
date('h:i', $hours_diff)." Hours";
?>

it shows: 02:00 Hours

but if you use a default UTC time:

<?php
date_default_timezone_set
('UTC');
$hours_diff = strtotime("20:00:00")-strtotime("19:00:00");
echo
"<br>". date('h:i', $hours_diff);
?>

it shows: 01:00 Hours.
up
-3
yan
5 years ago
caculate days between two date

<?php
 
// end date is 2008 Oct. 11 00:00:00
 
$_endDate = mktime(0,0,0,11,10,2008);
 
// begin date is 2007 May 31 13:26:26
 
$_beginDate = mktime(13,26,26,05,31,2007);

 
$timestamp_diff= $_endDate-$_beginDate +1 ;
 
// how many days between those two date
 
$days_diff = $timestamp_diff/86400;

?>
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-4
rlz
7 years ago
Finding out the number of days in a given month and year, accounting for leap years when February has more than 28 days.

<?php
function days_in_month($year, $month) {
    return(
date( "t", mktime( 0, 0, 0, $month, 1, $year) ) );
}
?>

Hope it helps a soul out there.
up
-4
Jacob Santos
1 year ago
Please note that incrementing a date using mktime in a loop is not proper. You could do it, except that there is a far better method found in the DateTime PHP class. Look at the documentation for DateTime::modify, DateTime::add (when supported) and DateTime::sub (when supported).

Also, adding seconds to a time is, well it isn't as easy as it seems, "Hey I'll just add 3600 seconds or 86400 seconds or x seconds!". The phrase once bitten, twice shy is quite applicable with the usage of adding seconds. If you ever had to 'fix' a time by calculating midnight to add the correct number of seconds, then you are doing it wrong.

Luckily, knowing is not a requirement, because DateTime and friends exists, removing the complexity for you.

So if given a choice of

mktime($seconds, $minutes, $hours+1);

and

$datetime->modify('+1 hour');

or

$datetime->add('P1H');

I'll go with the second choice, but probably not the third, unless I was using DateInterval::createFromDateString, so that other developers knew my intent.
up
-3
delfino dot salinas at gmail dot com
5 months ago
this function returns the number of days of a provided month and year, it consider the actual rules for leap years

(if the year is multiple of 4 which is not a multiple of 100 unless multiple of thousand then is a leap)
Regards, hope this function solves any issue :)

function daysinmonth($month,$year) {
$dim = 0;
switch ($month) {
    case 1:
    case 3:
    case 5:
    case 7:
    case 8:
    case 10:
    case 12:
        $dim=31;
        break;
    case 4:
    case 6:
    case 9:
    case 11:
        $dim=30;
        break;
    case 2:
        if($year%4==0) {
            if($year%100==0) {
                if($year%1000==0) { $dim=29; } else { $dim=28; }
            } else {
                $dim=29;
            }
        } else {$dim=28;}
        break;
    }
    return($dim);
}
up
-4
mogster at redesign dot no
5 months ago
Just a simple function to return mktime from a db (mysql) datetime (Y-m-d H:i:s):

function retMktimest($dbdate) {
  return mktime(substr($dbdate, 11, 2), substr($dbdate, 14, 2), substr($dbdate, 17, 2), substr($dbdate, 5, 2), substr($dbdate, 8, 2), substr($dbdate, 0, 4));
}
up
-8
contact at phpmember dot com
4 years ago
How many days have  passed since the beginning of the year.... regardless of what year it is...

<?php
//Carlos Galindo
//phpmember.com

$days = floor((time()-mktime(null,null,null,1,0,date("Y")))/86400);
           
echo
"$days days have passed";

//Good Luck
?>
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