by Matthew Lyon

Falsehoods Programers Believe About Time

Read this once, twice, and a third time. Then come back a week later and read it again.

Your Calendrical Fallacy Is...

And if you haven’t learned those lessons yet,

This leads to some interesting questions: If a user has set an alarm to wake up at 1 AM on that day, what happens? Does the alarm go off the hour after the midnight hour? Or does it go off during the hour before 2 AM? Or does it go off twice? Or do you just give up and not make the alarm go off at all and make your users miss their dead-of-night appointment?

Time zone news

Worth sticking in your RSS reader, if just to follow along with the continuing craziness.

A Brief History of (Modern) Time

Time reform offers a startling, deeply relevant explanation of how technological change happens.

The Radical Plan To Destroy Time Zones

If you thought my dystopian story in the second section sounded like utopia, you’re going to love this. These guys sound like tech bros to me, but if it’s your cup of tea…

It is ONE issue, and should be implemented world wide, all at once, on 2018 January 1 Monday. One common standard, world wide, overlaid with local and religious calendars as people want, no problem!

March 14th, 2018

I originally stated the entirety of North America writes the date 3/31/2018 , but it’s only the United States. Deepest apologies to my Canadian and Mexican colleagues, who write the date 31/3/2018 like the rest of the world. Both formats are backward. Dates should really be written 2018/03/31 .

March 15th, 2018

In addition to fixing several typos and clarifying a few sentences, I added a paragraph to the section on Daylight Saving Transitions about the difficulties with converting future clock times to UTC time.


Understanding Time Zones was first published to by Matthew Lyon on . All images (where applicable, unless otherwise noted) and text © Matthew Lyon 2019. It is published under the Creative Commons Attribution-Noncommercial-Share Alike 4.0 license. If you wish to reproduce any of this content in a commercial context, explicit permission is required. Please contact me directly.