Last month was the pandemic-distanced rendition of the Internationalization and Unicode Conference. This year is the 44th conference, or IUC44.  In addition to a tutorial (blogged about last month), I delivered a presentation: Earth, Moon, and abolishing leap seconds: the curious astronomy and politics of time(). Here are my slides, and a video of me talking through my slides.

My abstract was:

When does a minute have 61 seconds? Why does Posix time conflict with UTC? Why will California’s day be 25 hours long on November 1 2020? And why will that same day be shorter in the Yukon? If we don’t know how many days will be in this month, is that a problem? If we know our clocks could show the sun rising at 12:00 noon, many years in the future, should we avert that now? Will your software stumble at the next leap second? Should we abolish leap seconds altogether? Internationalization is about making software constructs match human requirements. Text strings and fonts get the glory, but time and date structures also need localization, and in surprising ways. This presentation digs into the role played by Earth and Moon orbits, and human choices, in the various data structures returned by your platform’s time() API. Suitable for all attendees (with plenty of links to specific specs and standards to satisfy the developers).

You can find the slides at (PDF, 3.5MB). You can find a video of the lecture at (MP4, 102.6MB). IUC sessions are allotted 70 minutes. I used 40 minutes of that for my lecture, and left the rest of the time for Question and Answer.

The title of this talk in the IUC44 program was, Internationalizing Date-time API Consistent with the Earth, Moon, and Leap Seconds. The Program Committee thought this title would make more sense to conference attendees, and might win more attendance. For this blog, I used my (rather quirkier) original proposed title.

This topic was a bit unusual for the IUC, perhaps a bit more philosophical than most. Time-keeping and calendars are an area where the human behaviour, and the underlying physics, are more complex and weird than the simple and tidy models with which software architects tend to represent them. In this, it is similar to writing systems and names, which get regular attention at the IUC. Time-keeping and calendars get less attention, but they provide a wonderful opportunity for information designers to check that we are not being blinded by our models, and to create richer models which better reflect the complex and weird reality. There is more to be explored about time-keeping and calendars.

IUC44 was 14-16 October, 2020, and was held virtually, by web conference. Plans for 2021 have not been announced yet, but the expectation is that, pandemic willing, IUC45 will be held in October 2021, in person, in Santa Clara, California.