Hacker News Reader

Showed up to a doctors appointment during their lunch break once because iCal supports the time format "TZ is whatever is local, trust me" and the device I used to add an appointment was set to UTC, not UTC+1.

My doctors calendar app vendor was pretty happy I found the root cause of their very occasional mystery appointment drift too.

View on HN

> “TZ is whatever is local, trust me”.

New years is midnight, local time, wherever you are. Trust me.

If I invite you (who lives in Spain, let’s say) to fly over and enjoy my New Year’s party (in New Zealand) it definitely is not going to occur at “midnight local time wherever you are” - Trust me.

(Actually there’s a famous missing person’s case related to a New Year’s party in New Zealand … I don’t think that timezones were part of what went wrong, but I can’t be sure.)

The correct behaviour would be to actually use the timezone field of an ISO date and not to assume that convertion to/from utc is always lossless.

A single number is not enough to store a datetime.

I blame databases for only storing half of the data and leaving the other half to the environment.

Reply on news.ycombinator.com