Javascript时间与PHP时间不一样

i'm having a (older) mobile webpage that shows the current time in the footer of that page. Now i've added some PHP code to it, to have the user select a starting time of a working timer.

I noticed that the Javascript time is 2 minutes ahead of the PHP time.

JS :

var currentTime = new Date()
var hours = currentTime.getHours()
var minutes = currentTime.getMinutes()
document.write(hours + ":" + minutes)

PHP :

echo date('H:i');

as i said, the difference is about 2 minutes, how is that even possible? both should be server time ??

Javacript is the time of the user...eg it may be 2 minutes if my pc time is 2 minutes ahead, or it might be difference in hours if different timezone from server!!

Php will always show server's time.

JS shows client side time. PHP shows time which is on server.