Question

I’m having a strange problem while trying to make a date from some user input using gmmktime(). It seems to always show my date as being one day behind when I convert it to a date for output. I have a date selection, and I am converting the date using the input from a month, year, and day drop down picker.

In my code, I have:

$inputDate = gmmktime(0,0,0,02,07,2012,0);
$inputDate = date("M d Y", $inputDate);

When this is output, the date that shows is Feb 06, 2012 instead of Feb 07, 2012. However if I change the gmmktime() to just mktime(), the date is correct and shows as the 7th.

Can someone explain why this is happening and what I need to do in order to use gmmktime() and have my dates displayed in the right format? Thanks!

Answer 1

The gmmktime() assumes that the entered date/time is GMT and automatically converts it to server time using date.timezone setting in php.ini. On my system which is +0500 GMT I get:

<?php
$inputDate = gmmktime(0, 0, 0, 2, 7, 2012);
echo date("M d Y H:i:s O", $inputDate);
// Feb 07 2012 05:00:00 +0500

Notice that I passed 0, 0, 0 as the time to the function but ended up getting 05:00:00. In your case it seems like your server is behind GMT so for every date you create using this function will be converted to -nnnn hours behind the specified date; for 00:00 GMT as the input this effectively means you get the previous date.

The workaround is simple, use gmdate() function to display dates created with gmmktime():

<?php
$inputDate = gmmktime(0,0,0,2,7,2012);
echo gmdate("M d Y H:i:s O", $inputDate);
// Feb 07 2012 00:00:00 +0000