Time comparison in php

Question

Possible Duplicate:
strtotime date weird result

I am trying to compare two times for an attendance system, i am trying to get the accurate time for Arkansas,USA but im not being to able to get the correct time. Please, guide me in the right direction if i am doing something wrong, part of my code:

$curTime =DATE("H:i A", strtotime('GMT-6'));

foreach($res as $r)
{
    $crs_id =$r['course_id']; 
    $query1 = "select * from tbl_course_time where course_id='$crs_id'";

     $res1 = $obj->querySelect($query1);


     $start_time  = DATE("H:i", STRTOTIME($res1[0]['start_time']));
     $end_time = DATE("H:i", STRTOTIME($res1[0]['end_time']));

    if ($curTime > $start_time && $curTime < $end_time) 
    {

      $qry="insert into tbl_attendance set         stud_id='$id',attd_date='$curDateForDB',attd_time='$curTimeForDB',course_id='$attd_courseId'";

    $res=$obj->queryInsert($qry);

    $result1 = "taken";
   }
}

It's giving me incorrect time's is it the GMT time im getting wrong or something else Any help would be greatly appreciated, Thank you

What are your outputs and what did you expect? Define "incorrect" — Jelmer, Dec 13 '12 at 14:44
I am getting 12 hour difference in time i am getting 20:46 PM for the 8:46 AM — jarus, Dec 13 '12 at 14:46

Anton · Answer 1 · 2012-12-13T14:47:43.657

1

Don't use strtotime('GMT-6') because GMT-6 is not a time; it's a time zone.

// gets the UTC time using gmdate() instead of date()
$utc_str = gmdate("M d Y H:i:s", time());

// get the UTC timestamp, should you need it
$utc = strtotime($utc_str);

If you're in PHP 5, the DateTime class is a very clean way to get times and also deal with time zone conversions.

Also, I encourage you to set your database up using UTC time, and convert the output to the user's time zone.

edited Dec 13 '12 at 14:47

answered Dec 13 '12 at 14:42

Anton

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i have tried using date time class when i try to do that, it just gives me incorrect time also, cud u please help with some code snippets, thanks – jarus Dec 13 '12 at 14:52
Does the above code give me time in seconds? – jarus Dec 13 '12 at 14:58
Yes, time is formatted in seconds starting at the UNIX epoch, 00:00:00 UTC on 1/1/1970. This is absolute, and time-zone free, so you can then convert to the local time. – Anton Dec 13 '12 at 14:59

score 0 · Answer 2 · answered Dec 13 '12 at 14:44

You're doing the gmt-6 business wrong. The following is on a server that's in GMT-6 already:

echo date('r');                     // Thu, 13 Dec 2012 02:40:00 -0600
echo date('r', strtotime('gmt-6')); // Thu, 13 Dec 2012 08:40:17 -0600

Note the 6 hour difference (and 17 seconds while I was typing up the strtotime bits). Doing the gmt-6 bit in strtotime forces PHP to apply a 6 hour difference to a string that's already in some timezone already.

Time comparison in php

2 Answers2