[RESOLVED] timezone problem

[atokatim]

Ok, i have been working on this for 2 days now and keep running into a bunch of problems. I am attempting to retreive a preset date and time from MySql in this format : 2/28/01 10:17 pm and change it to the timezone of whoever is viewing it. This particular time and date happens to be in a leap year.

My server is on Central time which is -6 hours. When a user sets their timezone, it is how many hours ahead or behind they are from me. example : -5 hours would be 1 hour ahead of me.

The problem i am having is if someone is 14 hours ahead of me, the time would be 12:17 pm and the date would be 3/1/01. I cannot get the AM and PM working correctly. and the date still stays 2/28/01.

here is my code :

<?
function getthedate($fulldate, $tmid) {
$changeam = 0;

$sql = mysql_fetch_object(mysql_query("SELECT * FROM members WHERE id = '$tmid'"));
$membertimezone = $sql->timezone; //  this would be 0 for -6 hours since it is the same as my server
$datecut1 = explode(" ", $fulldate);
$datecut2 = $datecut1[0];
$timecut1 = $datecut1[1];
$amorpm1 = $datecut1[2];

$datecut = explode("/", $datecut2);
$month = $datecut[0];
$day = $datecut[1];
$year = $datecut[2];

$timecut = explode(":", $timecut1);
$hour1 = $timecut[0];
$min = $timecut[1];
$hour = $hour1 + $membertimezone;
$finalhour = $hour1 + $membertimezone;
$amorpm = $amorpm1;
$changeam = 0;

if($hour >= 12){
	$finalhour = $hour - 12;
	if($finalhour == 0) $finalhour=12;
	if($finalhour == 24) $finalhour=12;
	if($finalhour > 12) {
		$finalhour = $finalhour - 12;
		$changeday = 1;
	}
	if($finalhour != 12 && $amorpm1 == "am"){
		$amorpm = "pm";
	} elseif($finalhour != 12 && $amorpm1 == "pm"){
		$amorpm = "am";
	}
}
if($hour <= 0){
	$finalhour = $hour + 12;
	if($finalhour == 0) $finalhour=12;
	if($finalhour <= 0){
		$finalhour = $finalhour + 12;
		$changeam = 1;
		$changedate = 1;
		$changeday = 1;
	}
	if($changeam != 1){
	if($amorpm1 == "am"){
		$changedate = 1;
		$changeday = 2;
		$amorpm = "pm";
	}
	if($amorpm1 == "pm"){
		$changedate = 0;
		$changeday = 0;
		$amorpm = "am";
	}
	}
}

if($changeday==1){  // go to next day
	$day = $day + 1;
	if(!checkdate($month, $day, $year)){
		$month = $month + 1;
		$day = 1;
		if(!checkdate($month, $day, $year)){
		$month = 1;
		$year = $year + 1;
		}
	}
}
if($changeday==2){ // go back a day
	$day = $day - 1;
	if(!checkdate($month, $day, $year)){
		$month = $month - 1;
		if(checkdate($month, 31, $year)) $day = 31;
		if(checkdate($month, 30, $year)) $day = 30;
		if(checkdate($month, 29, $year)) $day = 29;
		if(checkdate($month, 28, $year)) $day = 28;
		if(!checkdate($month, $day, $year)){
				$year=$year-1;
				$day = 31;
				$month = 12;
		}
	}
}


$finaltime = $month."/".$day."/".$year." ".$finalhour.":".$min." ".$amorpm;
return $finaltime;
}

?>

usage : echo getthedate("2/28/01 10:17 pm", $user_id);

is there any other way i can go about doing this? i am lost in my own code 🙁

thanks in advance for the help!

[Installer]

I won't go into your method of storing/formatting datetimes (see this thread for that).

Anyway, try this:

function getthedate($fulldate, $tmid) 
{ 
    $sql = mysql_fetch_object(mysql_query("SELECT timezone FROM members WHERE id = '$tmid'")); 
    return date('n/j/y g:i a', strtotime($sql->timezone, strtotime($fulldate)));
}

[atokatim]

I could use that, but i need to get the timezone difference of a prior date and time, say 5 days ago or 3 months and 10 days ago for each user that would view the entry date and time....which is stored in the database as my server date and time.

[Installer]

I thought that was what you were passing to the function as "$fulldate". Anyway, using "strtotime()" you can get just about any date and time as offset from another.

In the function you posted you query for all the table columns, but "timezone" is the only one you use.

[atokatim]

ok, i will have to look into that. I may have figured out what i am missing. i am converting the strings that return as pm to 24 hour time so that i can use the function mktime to get the am or pm for that time for each person.

[atokatim]

Ok, I have finally gotten it to work....BUT. is there any way possible to automatically adjust for daylight savings time. I know that some areas do not adjust to daylight savings time. My server will probably automatically adjust. I am not sure. still learning linux. any way to do this from a set date and time?

I had to convert the time to 24 hour time and go from there.

Server Time Zone = -6

$fulldate = "5/25/06 5:49 pm";
$tmid = 1;

The Code :

function getthedate($fulldate, $tmid) {

$sql = mysql_fetch_object(mysql_query("SELECT * FROM members WHERE id = '$tmid'"));
$membertimezone = $sql->timezone; // returns 0 for -6 ....  1 for -5 ......  2 for -4 ..... and so on.
$datecut1 = explode(" ", $fulldate);
$datecut2 = $datecut1[0];
$timecut1 = $datecut1[1];
$amorpm = $datecut1[2];

$datecut = explode("/", $datecut2);
$month = $datecut[0];
$day = $datecut[1];
$year = $datecut[2];

$timecut = explode(":", $timecut1);
$min = $timecut[1];
$hour = $timecut[0];

if($amorpm == "pm") {
	$hour = $hour + 12;
}
$hour = $hour + $membertimezone;
$finalhour = $hour;
if($hour >= 24){
	$hour = $hour - 24;
	$finalhour = $hour;
	$changeday=1;
}
if($hour < 0){
	$hour = $hour + 24;
	$finalhour = $hour;
	$changeday=2;
}
if($hour == 0){
	$finalhour = 0;
	$hour = 12;
}

$finalhour2 = $hour;

if($changeday==1){
	$day = $day + 1;
	if(!checkdate($month, $day, $year)){
		$month = $month + 1;
		$day = 1;
		if(!checkdate($month, $day, $year)){
		$month = 1;
		$year = $year + 1;
		}
	}
}
if($changeday==2){
	$day = $day - 1;
	if(!checkdate($month, $day, $year)){
		$month = $month - 1;
		if(checkdate($month, 31, $year)) $day = 31;
		if(checkdate($month, 30, $year)) $day = 30;
		if(checkdate($month, 29, $year)) $day = 29;
		if(checkdate($month, 28, $year)) $day = 28;
		if(!checkdate($month, $day, $year)){
				$year=$year-1;
				$day = 31;
				$month = 12;
		}
	}
}
$amorpmis = mktime($finalhour, $min, 0, $month, $day, $year);
$amorpm = strftime("%P",$amorpmis);

if($finalhour2 > 12) $finalhour2 = $finalhour2 - 12;

$finaltime = $month."/".$day."/".$year." ".$finalhour2.":".$min." ".$amorpm;
return $finaltime;
}

Thanks in advance once again!

[Installer]

This function:

function getthedate($fulldate, $tmid) 
{ 
    $sql = mysql_fetch_object(mysql_query("SELECT timezone FROM members WHERE id = '$tmid'")); 
    return date('n/j/y H:i', strtotime($sql->timezone . ' hours', strtotime($fulldate)));
}

will do exactly what you're trying, without success, to get this function:

function getthedate($fulldate, $tmid) { 

$sql = mysql_fetch_object(mysql_query("SELECT * FROM members WHERE id = '$tmid'")); 
$membertimezone = $sql->timezone; // returns 0 for -6 ....  1 for -5 ......  2 for -4 ..... and so on. 
$datecut1 = explode(" ", $fulldate); 
$datecut2 = $datecut1[0]; 
$timecut1 = $datecut1[1]; 
$amorpm = $datecut1[2]; 

$datecut = explode("/", $datecut2); 
$month = $datecut[0]; 
$day = $datecut[1]; 
$year = $datecut[2]; 

$timecut = explode(":", $timecut1); 
$min = $timecut[1]; 
$hour = $timecut[0]; 

if($amorpm == "pm") { 
    $hour = $hour + 12; 
} 
$hour = $hour + $membertimezone; 
$finalhour = $hour; 
if($hour >= 24){ 
    $hour = $hour - 24; 
    $finalhour = $hour; 
    $changeday=1; 
} 
if($hour < 0){ 
    $hour = $hour + 24; 
    $finalhour = $hour; 
    $changeday=2; 
} 
if($hour == 0){ 
    $finalhour = 0; 
    $hour = 12; 
} 

$finalhour2 = $hour; 

if($changeday==1){ 
    $day = $day + 1; 
    if(!checkdate($month, $day, $year)){ 
        $month = $month + 1; 
        $day = 1; 
        if(!checkdate($month, $day, $year)){ 
        $month = 1; 
        $year = $year + 1; 
        } 
    } 
} 
if($changeday==2){ 
    $day = $day - 1; 
    if(!checkdate($month, $day, $year)){ 
        $month = $month - 1; 
        if(checkdate($month, 31, $year)) $day = 31; 
        if(checkdate($month, 30, $year)) $day = 30; 
        if(checkdate($month, 29, $year)) $day = 29; 
        if(checkdate($month, 28, $year)) $day = 28; 
        if(!checkdate($month, $day, $year)){ 
                $year=$year-1; 
                $day = 31; 
                $month = 12; 
        } 
    } 
} 
$amorpmis = mktime($finalhour, $min, 0, $month, $day, $year); 
$amorpm = strftime("%P",$amorpmis); 

if($finalhour2 > 12) $finalhour2 = $finalhour2 - 12; 

$finaltime = $month."/".$day."/".$year." ".$finalhour2.":".$min." ".$amorpm; 
return $finaltime; 
}

to do.

[atokatim]

WOW. i feel retarted 🙂) I really appreciate that! i knew there had to be a better and easier way, but i just could not figure it out. Will that adjust to daylight savings time too?

[Installer]

As for daylight time, I don't know. It varies so much that I think you have to hand code for it on a timezone-by-timezone basis. Maybe someone else knows an easy way.

Glad I could help. 🙂