How to convert string with date and time AM/PM to 24 Hour mysql timestamp format

Question

I am trying to insert date and time into mysql datetime field from a string having following dd/mm/yyyy hh:mm:ss AM/PM format:

20/10/2014 05:39 PM

20/10/2014 05:39 AM

I know MYSQL timestamp format is yyyy-mm-dd hh:mm:ss or 0000-00-00:00:00:00

So if I do:

$s = substr("20/10/2014 05:39 PM", 0, 10);
$h = date("G:i", strtotime($s));
list($day, $month, $year, $hour, $minute) = split('[/ :]', "20/10/2014 05:39 PM"); 
echo $d1me = $year . '-' . $month. '-' .  $day . ' ' . $h;

I get 2014-10-20 19:00

So I guess there is a problem with date_default_timezone_set() function, How to solve this and get expected result?

20/10/2014 05:39 PM     ->   2014-10-20 17:39:00

20/10/2014 05:39 AM     ->   2014-10-20 05:39:00

How to do it?

Answer 1

MySQL already knows how to parse many different types of date strings natively, using the STR_TO_DATE() function in combination with format strings used by DATE_FORMAT().

So, I would not involve PHP in this process at all, and instead allow MySQL to parse the input itself.

The format string you need to use is %d/%m/%Y %h:%i %p, where the %p represents AM/PM.

You can use the entire expression right in your INSERT statement, passing the strings directly from PHP assuming you have validated their format already.

INSERT INTO your_table (timestamp_column) VALUES (STR_TO_DATE('20/10/2014 05:39 PM', '%d/%m/%Y %h:%i %p'));

...will correctly insert the DATETIME value 2014-10-20 17:39:00 into your table.

If you really prefer to do it in PHP first, use DateTime::createFromFormat() (PHP 5.3+) using the format string 'd/m/Y H:i A'

$d = DateTime::createFromFormat('d/m/Y H:i A', '20/10/2014 05:39 PM');
var_dump($d);

class DateTime#2 (3) {
  public $date =>
  string(26) "2014-10-20 17:39:00.000000"
  public $timezone_type =>
  int(3)
  public $timezone =>
  string(15) "America/Chicago"

To get a MySQL formatted date back out of it,

echo $d->format('Y-m-d H:i:s');
// 2014-10-20 17:39:00

If you are in the deeply unfortunate situation of having a PHP version older than 5.3, you can achieve similar results with strptime() but you'll need to assemble its array output into MySQL's string format.