How to save datetimes for future events

Re:How to save datetimes for future events by gravypod on Monday March 23, 2015 @05:23PM (#9253431)

Why not just use a unix timestamp and convert to the local time format of all users? Is that a poor solution for this? Most unix timestamp to Date converters already take DST into account.

This also fixes the "MM/DD/YYYY", "DD/MM/YYYY", and "YYYY/MM/DD" fiasco as you can rely that the users computer is configured to the correct timezone/localization settings.

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Re:How to save datetimes for future events by andrewfong on Monday March 23, 2015 @05:49PM (#9253553)

Because the Unix timestamp is based on UTC and may not accurately capture the user's intent if the DST rules change in between when the timestamp is created and when the timestamp is read.

That is, suppose I schedule an event on 2016 April 1, at 10am in San Francisco, California. Under current DST rules, this translates into 2016 April 1, 5pm UTC or a Unix timestamp of 1459530000.

Now suppose DST is abolished in California between now and the event occurring. A Unix timestamp of 1459530000 would then correspond to 2016 April 1, at 9am in San Francisco, which is one hour too early.

Another way to think about this: You have to apply the DST conversion rules applicable at the time the event was created, NOT the (potentially different) rules at the time the event occurs. But maintaining different sets of conversion rules based on when an event is scheduled is a lot more cumbersome than simply recording the local time and location.

[ Parent | on HN ]