Time or Time interval conversion with PHP

[mazraara]

i have the below given time interval options in a dropdown (those are strings)

<select name="CSSAtapsClient[client_time_window][0]" id="client_time_window_0">
<option value="5702">7am - 10am</option>
<option value="5703">10am - 1pm</option>
<option value="5704">12pm - 3pm</option>
<option value="5705">3pm - 6pm</option>
<option value="5706">6pm - 9pm</option>
<option value="5707">7pm - 10pm</option>
<option value="5708">9pm - 12am</option>
<option value="5709">12am - 7am</option>
</select>

I need to convert these intervals for a specific GMT time zone. for example lets say its in GMT +8 and i need to convert it to GMT +10 and it can be done by adding 2 hours.

so if the given time interval is, 7am - 10am (GMT + it should come as 9am - 12pm (GMT +10)

What is the best way to convert this kind of a time interval ? The issue i am seeing here is its a string (time interval).

Appreciate an early reply.

EDIT 1

I am converting to only Australian states so there is no chance of getting a day as difference when converting. pls check this link http://www.timebie.com/tz/australiatimezone.php

[mazraara]

Found this answer...

 

<?php

function is_am_pm($str){
if(strpos($str, "am") !== false || strpos($str, "AM") !== false) return "am";
if(strpos($str, "pm") !== false || strpos($str, "PM") !== false) return "pm";
}
function get_only_int($str){
return (int) preg_replace('/\D/', '', $str);
}
function gmt_to_gmt($str,$from_gmt,$to_gmt = "GMT +10"){
if(!is_numeric($from_gmt)) $from_gmt = get_only_int($from_gmt);
if(!is_numeric($to_gmt)) $to_gmt = get_only_int($to_gmt);

$temp_time = explode("-",$str);

$begin_time_s = is_am_pm($temp_time[0]);
$begin_time = get_only_int(trim($temp_time[0]));
$end_time_s = is_am_pm($temp_time[1]);
$end_time = get_only_int(trim($temp_time[1]));

$time_diff = $to_gmt - $from_gmt;
$begin_time = $begin_time + $time_diff;
$end_time = $end_time + $time_diff;

if($begin_time > 13){
if($begin_time_s == "am"){
$begin_time -= 12;
$begin_time .= "pm";
}else{
$begin_time -= 12;
$begin_time .= "am";
}
}else{
$begin_time .= $begin_time_s;
}
if($end_time > 13){

if($end_time_s == "am"){
$end_time -= 12;
$end_time .= "pm";
}else{
$end_time -= 12;
$end_time .= "am";
}
}else{

$end_time .= $end_time_s;
}

return $begin_time . " - " . $end_time;
}
echo gmt_to_gmt("7am - 11pm", "GMT +0" , "GMT +2");
?>

 

but its not displaying some parts correctly.  when 7am - 11pm is given it should return 9am - 1pm but here its outputting 9am - 13pm

Edited September 30, 2013 by mazraara

[Ch0cu3r]

Change

if($end_time > 13){

to

if($end_time >= 13){

[mazraara]

Thanks a lot. but i am thinking why does it returns 12am - 1am when i input 10am - 11pm. Actually it should be 12 pm not 12 am

 

Appreciate your help

Edited September 30, 2013 by mazraara

[Shareek]

bump

[kicken]

Rather than trying to convert 7pm-11pm, why not just leave it as is? Something like 7pm is a relative time, there is no need to be trying to do timezone calculations on it. Leave 7pm as it is and you can handle timezone differences when you generate an absolute date later on.

 

What exactly are you attempting to do?

[Barand]

You could try this method

$perth = new DateTimeZone('australia/perth');
$darwin = new DateTimeZone('australia/darwin');
$sydney = new DateTimeZone('australia/sydney');

$time = DateTime::createFromFormat('G:ia', '10:00am', $perth);
echo $time->format('G:ia') . " Perth<br>";

$time->setTimezone($darwin);
echo $time->format('G:ia') . " Darwin<br>";

$time->setTimezone($sydney);
echo $time->format('G:ia') . " Sydney<br>";

/*** RESULTS **********
10:00am Perth
11:30am Darwin
12:00pm Sydney
***********************/