You think timezones are bad now? Just you wait.

by Austin Gibbons

What do sales folk, web programmers, and MMORPG clan leaders have in common? We all have to work with with people who are only online when we are asleep. My sincerest appreciation to my dear friends in London, Israel, and Singapore for your everlasting patience and our 12 hour ping-pong emails.

Of course, this does not hold a candle to the issues that some brave programmers have had to handle. I love this video from Computerphile describing the insanity of timezones if you have yet to have had the pleasure of running into one of the boundless pitfalls, or here’s a fun example that I recently encountered while researching the Sao Paulo timezone

Between 1963–10–23 and 1963–12–09 in Brazil only Minas Gerais, Espirito Santo, Rio de Janeiro and Sao Paulo had summer time, but on request a split from America/Sao_Paulo was rejected with the reasoning that since 1970 the clocks were the same in the whole region

What a dilemma. What time was it in fall of 1963 in Santa Catarina one second after 1963–10–22 11:59:59? Because of regional drought, they did not observe summer time that year, so for the people actually experiencing that time it was 1963–10–23 12:00:00, but because it happened before 1970, the start of Universal Coordinated Time, it does not differ from the standard Brasília Summer Timezone (BRST), where the time was 1963–10–23 01:00:00. What are you going to build into your Historic-Brazilian-Time-Calculator? Quoth Computerphile:

What you do is you put away your code, you look at the first people … and you thank them very much for making it open source … and you never ever look at it again, for that way lies madness.

If you are an engineer with these problems checkout moment, it has been enormously helpful at Periscope and I recommend it whole heartedly.

But hold your horses! This is not another enumeration of the dangers of timezones: I drew you in with the U.S.S. Enterprise picture, remember? This is a whole new problem that the future coders of the world will have to handle: relativity. Yup, space ‘n stuff. You think you have trouble converting from PDT to BRST today, let me pose to you this question:

You’re having a friendly chat with Captain James T. Kirk, and he signs off with “Great, let’s rendezvous Friday at oh-seven hundred hours” and drops the sub-space communication link. It’s currently 7:00 am on Tuesday. How many hours until your meeting?

You have 72 hours until you check-in with Captain Kirk, right? Well there’s a problem — The U.S.S. Enterprise is traveling at 30,000 km/s, roughly one tenth the speed of light and you just so happen to be at rest in the universal reference frame. When three days has elapsed for Kirk, you’ll have experienced an additional 22 minutes; your meeting starts at 7:22!

In the future, if there are spaceships traveling at speeds attainable today of 30 km/s — a mere one hundredth of a percent of the speed of light — the spaceship would observe around 1.5 less seconds every ten years. Added to the list of timezone rules based on location, year, season, religion, and the dynamic speed of the earth will come other problems from humans moving at relativistic speeds or being near a gravitational well. Timezones will have to evolve to become dynamic with respect to each other, it will not be simple enough to use static offsets that change at most once every few months — they will be continually become further out of sync while under the effects of time dilation, and yet even this will not be deterministic as the ship accelerates and decelerates on its voyage across the galaxy.

Fortunately Satellites in use for GPS are actually dealing with this problem today; to an extent someone is already foraging this territory. There may come a day, however, when you ask someone what timezone they observe and receive the answer ERT: Enterprise Relative Time.

Originally published at on October 1, 2015.