Time and cookies question

[stew1]

Hi,

Is there anyway (say from the request header) of assertaining the time on the clients PC? The reason I ask is that I want to set a cookie that will only last for a short time (typically 15 minutes). If I set it this way.....

setcookie("seshid",$seshid, time() + $sesh->expiry_time,"/",".mydomain.com",0);

and the client PC's clock is 14 minutes fast then the cookie will only last for 1 minute.

Any ideas??

Regards

Stew

[mogster]

Are you sure?
As far as i know, client time means nothing to php. And the cookie-value $seshid's timestamp is a set value (not dependant on the pc clock), and will be measured against some other set value (in php) to define wether or not the time has expired.

knutm

[stew1]

I'm sure!

If the cookie is set at 9:00 am (+ 15 minutes expiry time) (server time) and the time is 9:14 am on the client side then the browser will delete the cookie 1 minute after it has been set.

I know small differences in time probably don't make that much difference in applications where the cookie will only last on a per session basis or where they might be set for a day or even a month, but I want to make sure all information about a previous session is removed after the alloted period (in this case 15 minutes) of in-activity has expired.

[mogster]

Well, I still have a hard time believing this 😉

But you can still work around it, depending on how your script controls the time.
Use session cookies (no time setting in cookie), then set time manually:

<?PHP
$timed = time();
## Set session_id ##
setcookie("seshid", $seshid);
## Set manual timestamp ##
setcookie("runtime", $timed);
?>

<?PHP
$time_limit = time() - 1500;
## Check wether time is past timelimit ##
if($runtime < $time_limit) {
## Unset session (or you may start a new) ##
setcookie("seshid", "");
header("Location:another_page.php");
}
?>

knutm