time conversion from PDT submitted from form to GMT

[pwnedbyphp]

Hello all,

 

I have a form value for time in HHMM 24 hr format which is in PDT and I want to simply convert this time to GMT. The server that the script resides on is on GMT of course but I want the user to just put in PDT and let the script do the calculation.

 

What would be the easiest way to get POST data in HHMM format and then do the conversion?

 

Thanks!

[gwolgamott]

A lot of people asking about time lately...

 

Here's an answer I gave a while back

 

you'll want to use this though for your code: echo(date("H:i",$server_local_time));  // will display something like: 23:03

 

Run a test to see what the time stamp is producing, if it is wrong then just subtract/add the appropriate number of hours to the result you desire.  You could use the UNIX time stamp function time() and add/subtract appropriate number of seconds for the time difference of your timezone, then store that and run a date() function on that variable.

 

<?php
$time_zone_difference = 21600;        //6 hours worth of seconds = 60*60*6
$server_local_time = time();              //gives UNIX time (the number of seconds since January 1 1970 00:00:00 GMT)
$server_local_time = $server_local_time - $time_zone_difference; //subtracts additional time
echo(date("D F d Y",$server_local_time));  // will display something like: Wed April 14 2010   
?> 

 

 

EDIT:

reference code for date() so if you want to use hours obviously... instead of calendar date. Here is the list

Required. Specifies how to return the result:

 

    * d - The day of the month (from 01 to 31)

    * D - A textual representation of a day (three letters)

    * j - The day of the month without leading zeros (1 to 31)

    * l (lowercase 'L') - A full textual representation of a day

    * N - The ISO-8601 numeric representation of a day (1 for Monday through 7 for Sunday)

    * S - The English ordinal suffix for the day of the month (2 characters st, nd, rd or th. Works well with j)

    * w - A numeric representation of the day (0 for Sunday through 6 for Saturday)

    * z - The day of the year (from 0 through 365)

    * W - The ISO-8601 week number of year (weeks starting on Monday)

    * F - A full textual representation of a month (January through December)

    * m - A numeric representation of a month (from 01 to 12)

    * M - A short textual representation of a month (three letters)

    * n - A numeric representation of a month, without leading zeros (1 to 12)

    * t - The number of days in the given month

    * L - Whether it's a leap year (1 if it is a leap year, 0 otherwise)

    * o - The ISO-8601 year number

    * Y - A four digit representation of a year

    * y - A two digit representation of a year

    * a - Lowercase am or pm

    * A - Uppercase AM or PM

    * B - Swatch Internet time (000 to 999)

    * g - 12-hour format of an hour (1 to 12)

    * G - 24-hour format of an hour (0 to 23)

    * h - 12-hour format of an hour (01 to 12)

    * H - 24-hour format of an hour (00 to 23)

    * i - Minutes with leading zeros (00 to 59)

    * s - Seconds, with leading zeros (00 to 59)

    * e - The timezone identifier (Examples: UTC, Atlantic/Azores)

    * I (capital i) - Whether the date is in daylights savings time (1 if Daylight Savings Time, 0 otherwise)

    * O - Difference to Greenwich time (GMT) in hours (Example: +0100)

    * T - Timezone setting of the PHP machine (Examples: EST, MDT)

    * Z - Timezone offset in seconds. The offset west of UTC is negative, and the offset east of UTC is positive (-43200 to 43200)

    * c - The ISO-8601 date (e.g. 2004-02-12T15:19:21+00:00)

    * r - The RFC 2822 formatted date (e.g. Thu, 21 Dec 2000 16:01:07 +0200)

    * U - The seconds since the Unix Epoch (January 1 1970 00:00:00 GMT)

[pwnedbyphp]

This is what I have currently but it doesn't calculate correctly. So if the data is coming in as 4 digits representing PDT, I should have to add 7 hours to make it GMT.

 

$time_zone_difference = 25200; // 7 hours x 3600
$server_local_time = time($_POST['stime']);
$server_local_time = $server_local_time + $time_zone_difference;
$stime=date("Gi",$server_local_time);
echo $stime;

 

If I submit 0200 as my POST time i get 118 as the result. If I echo the first server_local_time i get 1273256421. Somehow the date function interpreted 1273256421 + 25200 as 118.

 

I think the approach is all wrong but I appreciate the help so far. I Just wanted to see if there was an easy way to take a 4 digit "time" value in PDT and convert to another timezone within php.

 

[roopurt18]

$time_zone_difference = 25200; // 7 hours x 3600

You shouldn't perform timezone conversions in such a way.

 

Which version of PHP do you have? Is it at least 5.2?

[pwnedbyphp]

I'm using php 5.1.6.

[gwolgamott]

That could just calculates 7 hours plus current time of the server.

 

If you are using a specified date (sorry my bad there) you will not want to use time() as it gives you current time and voids anything with the () of time(). So anything within the parantethese is ignored. You're getting result for whats probably 7 hours ahead of your server or something like that.

 

If you already have a posted time though this can be very simply then, I didn't realize (read, pay attention...etc...etc..) to what you wanted.  Then all you really need to do is something like this:

[gwolgamott]

Forgot the code there sorry

 

 

 
// here's another way of doing it if you have the HHMM format stored someplace as for example 0200
<?php
$my_time = "2100"; // HHMM time format    // or for 02:00
$my_calc = str_split($my_time, 2);      // explode(":",$my_time);

echo $my_time." My Time <br>";
echo $my_calc[0]." My Hour <br>";
echo $my_calc[1]." My Minutes <br>";

$my_calc[0] = $my_calc[0] + 7; // adds seven hours

if ($my_calc[0] > 24)
{
$my_calc[0] = $my_calc[0] - 24; 
} // retain 24 hour

if ($my_calc[0] < 10)
	{
	$my_calc[0] = "0".$my_calc[0];
	} // to retain 2 digits for hour

$new_time = implode("",$my_calc);

echo $new_time." My New time Plus 7 Hours";
?>

[pwnedbyphp]

Awesome it works!

 

Thanks for the help gwolgamott!