28 Mar 2005

Time-Wasting Time

I’ve always felt that Daylight-Saving Time (which kicked in here over the weekend) is a slightly odd solution to an unclear problem. If there’s one thing you should try not to muck about with too much it’s the time, right? Yet we change every clock twice a year. When the clocks go forward you have a chunk of time that never happened; worse still, when going back the same time period occurs twice. Few programmers would ever devise such a system, whatever the (dubious) practical benefits (there’s definitely a strong consistency/elegance mindset amongst coders; politicians are at the opposite end of that spectrum, which is why life rarely gets simpler).

It’s more screwed-up than you might realise. Some parts of the world observe DST, others don’t. Some places regularly change their minds. Different areas switch the clocks on different dates. Indiana is a mess. Combined with the complexities of time zones (including daft half- and quarter-hour offsets), leap years/seconds, and date/time formats, you can imagine how much effort goes into just keeping software’s time-handling accurate.

• Interesting and confusing facts about time and time zones
• End Daylight Saving Time
• World Time Server
• How to handle international dates and times in PHP and MySQL
• The tz database