Question

I have a presenter and viewer on site collaborating globally
They are both registered users with their location (city/state/country) stored in mysql

meeting times are displayed to both users on php based on one of the users local time, i would like other user’s time adjusted accordingly based on first user’s location. (keeping in mind daylight saving in USA)

or alternatively

i would like all USA timezone self updating clocks displayed on the webpage

how can this be done?

Answer 1

In the database, I would store the original meeting time in UTC. I would also have a field on the user table to assign a TZ category.

A simple if/then for daylight savings is active on that date, and then convert the time.

I’d use php for all of it. Since you can combine the db pull to include UTC + TZ alteration in the same query. Then, adjust for daylight savings if necessary.

• pull meeting time from meeting table and TZ info from user table (same query)
• check for daylight savings
• adjust time based on the above
• send results to page.