Handle_cross_time_zone.md

Handle cross time zone

Solution

If we have clients in different timezone, how should we store the time data?

I think the best way is that client side way convert to timestamp, or give timezone info in API.

Other approach

But what if another team member suggest just store origin datetime or timestamp?

Would that cause problems? and how to prove that?

Store datetime

If current time is GTM +0 2023-02-09 00:00:00, and we have two client in two timezones, which are GMT +2 and GMT +3.

If we just store the datetime from client-side, We will store two different datetime even both of them are the same time.

Store timestamp by serverside

If current time is GMT +0 2023-02-09 00:00:00, which timestamp is 1675900800

The client timezone is GMT +2 2023-02-09 02:00:00, which timestamp is also 1675900800

And the server timezone is GMT +8 2023-02-09 08:00:00, which timestamp is also 1675900800

If we convert the client-side to timestamp, in GMT + 0 would be 1675908000, and GMT + 8 would be 1675879200

When the client send another API want to get data stored in GMT +2 2023-02-09 02:00:00, In server parse this datetime with GMT +8,

example: php

dd(Carbon::parse('2023-02-09 02:00:00')->timestamp);

Result timestamp would be 1675879200, which is correct timestamp stored.

But, we’ll still have two problems,

  1. We can’t display the correct datetime unless we know both server and client timezone and how data stored. It can be complex.
  2. Still have wrong time if client have multiple timezones.
    • if we have another client with GMT + 3, the timestamp would be 1675882800, which timestamp won’t match if get data API called from GMT + 2.
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