[stoney]

> You have to tell it a time zone or else the calendar app will not know what time you mean

It seems logical to me that whatever time I write in my calendar app is the time that I expect something to happen. I.e. it is the local time at wherever I happen to be. If I put in a meeting at 4pm on 8/7/2011, then I expect an alarm to sound whenever the local time is 4pm on 8/7/2011.

That's how my paper diary works (or used to work when I had one) - if I am planning for a future event where I will be in a different time zone, I simply write down the local time of the event.

[caf]

That doesn't sound at all logical to me. The phone conference is scheduled for a particular time, eg 10am in Montreal. The other meeting participants do not care that it is now 10am in Mombasa, where your phone happens to be at the moment - they will not be at the meeting for another 7 hours anyway.

Your other way also allows for the same event to happen twice, at different times, which is entirely unexpected.

[stoney]

Yes, very true. Doesn't work very well for events where people are attending from multiple time zones. I was thinking more of events that I attend in person.

But I'll use the paper diary example again - if I was in Mombassa and was due to have a phone conference at 10am Montreal time, I would write "6pm - Phone conference" in my diary (assuming that is indeed the correct local time).

And in your example, yes, it would be easier for me if I could tell my calendar that it is "10am, montreal time, please adjust that to mombassa time". So I guess my ideal solution would be a calendar app that works the way I described unless I specifically override it.

Anyway, I think this proves the point that time is hard.

[hammerdr]

Alternatively, we could all just use UTC+0 and never worry about time zones again! :)

[dandelany]

Most useful calendar apps these days allow you to share events, or invite others to an event. What happens when you invite someone who lives in another timezone? There's no good way to handle this that doesn't involve taking timezones into consideration.

[chrisbolt]

What is supposed to happen when you take a flight at 4:10pm on 8/7/2011 and land before 4:10pm on 8/7/2011 (local time)? Do you get the alarm twice?

[Archaeum]

I think that would be the expectation of most non-engineers, assuming they set the new time zone before arriving and if they even considered edge cases like that. It's also how most alarms work, whether mechanical or digital.

[stoney]

I think that's pretty hard to do in these post-concord days?

Though if you lived close to a time zone border it could be a problem. There are towns straddling the Queensland-New South Wales border in Australia. There is a one hour time difference between the states for half of the year (NSW does daylight saving, QLD does not). I've always wondered how local businesses deal with that.

[neckbeard]

It is incredibly easy to arrive hours before you leave. Just fly East across the dateline (like Aus to North America).

And I've even lost a birthday flying back in the other direction. Great scheduling, that.

[masklinn]

> It is incredibly easy to arrive hours before you leave. Just fly East across the dateline (like Aus to North America).

Or use a fast plane going west (Concorde used to take ~3h for London to NYC, and NYC is on UTC-5, so passengers on Concorde would arrive "2h before they left").