How to find difference between two dates obtained as a response from PHP? I'm storing the response dates in two javascript variables

Question

function chatbox($to_user_id,to_name,from_name,$from_user_id,$user_last_activity) 
{
    var to_user_id = $to_user_id;
    var from_user_id = $from_user_id;
    var status = "";
    var last_seen = $user_last_activity;
    var current_time = "<?php
                          echo $current_timestamp = date("Y-m-d H:i:s");
                        ?>"; 
}

I am fetching $user_last_activity from database using php and passing it to the javascript function chatbox. And i am getting the current time from php date function. How to compare these two javascript variable to get the time difference in sec, min and hour.

score 1 · Answer 1 · answered Mar 07 '20 at 13:36

1

Please use php as

<script>
var date= "<?php echo $current_timestamp = date('Y-m-d H:i:s'); ?>";
</script>

Remember you can't use " in ' ' string and ' in " " string because it will consider the string end point.

answered Mar 07 '20 at 13:36

Mr Perfect

116
8

Okk.. But how to get the difference between these two dates? – Mar 07 '20 at 13:38
You can use javascript dates instead of php dates – Mr Perfect Mar 07 '20 at 13:39
Or use php date difference and store it to any input field an call it's value in function – Mr Perfect Mar 07 '20 at 13:40
But i thnk date_diff() provides difference in days only – Mar 07 '20 at 13:56
This should help https://stackoverflow.com/questions/12520145/number-of-minutes-between-two-dates/12520198 – Mr Perfect Mar 07 '20 at 13:59
Bro, I've seen that but how to apply strtotime() to $user_last_activity which stored the value of last login time of user?. It's not working – Mar 07 '20 at 14:02
Do you store $user_last_activity as current_timestamp? – Mr Perfect Mar 07 '20 at 14:03
You can use this as "strtotime($user_last_activity)-time()" – Mr Perfect Mar 07 '20 at 14:05
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/209213/discussion-between-ankit-jaishwal-and-mr-perfect). – Mar 07 '20 at 16:30

score 1 · Answer 2 · answered Mar 08 '20 at 02:57

Once you fix the quote issue, there is another issue here:

$current_timestamp = date("Y-m-d H:i:s")

That will produce a timestamp in the format (using moment.js tokens) YYYY-MM-DD HH:mm:ss (e.g. 2020-03-08 16:38:21), which is not supported by ECMA-262. You don't show how the timestamp is converted to a Date, but I'll guess you're using the built–in parser like:

var d = new Date(current_time);

However, since parsing of unsupported formats is implementation dependent, some browsers will return an invalid date.

Also, the PHP code produces a "local" date for the server, presumably it's set to UTC. Where browsers do parse a date in the format YYYY-MM-DD HH:mm:ss, it will almost certainly be as local to the browser's host system so will represent a different moment in time from the initial timestamp if the two systems have different settings.

The OP doesn't say what format $user_last_activity is. Presumably it's another timestamp, so it will have the same issues with parsing.

Once the above issues are sorted, you can get the difference in milliseconds between two dates by simply subtracting one from the other, see Difference between dates in JavaScript. The time difference can then be converted to days, hours, minutes, whatever.

Thanx. I got it. Btw i have solved it by changing the logic. I just used strtotime() to both $user_last_activity and $current_time in the php page from where i'm calling JavaScript chatbox() function and find the difference there and then passing the difference in the function. Well, i'll try your method too. — , Mar 08 '20 at 05:49

score 1 · Accepted Answer · answered Jun 26 '20 at 11:52

I have solved it by changing the logic. I just used strtotime() to both $user_last_activity and $current_time in the php page from where i'm calling JavaScript chatbox() function and find the difference there and then passing the difference in the function.

How to find difference between two dates obtained as a response from PHP? I'm storing the response dates in two javascript variables

3 Answers3