New time zone definitions release for 2020
Recently I received a notification on my phone announcing that new time zone definitions were available and that I needed to restart my phone. I don’t recall seeing this type of notification in the past, but based on some of my recent data analytics projects I had a good idea what this might be about.
The Internet Assigned Numbers Authority (IANA) maintains a database, tz database, of code and data that represent the history of local time for many locations around the globe. Using the time zone definitions contained in the tz database it is possible to determine the UTC offset for a particular time zone at a particular date. This includes definitions for the start and end of daylight savings time and also complete changes to the time zone for a country or region. This information changes more frequently than one might assume. For example, a recent change to the database added Fiji starting to observe daylight savings time from the second Sunday in November from 2019 instead of the first Sunday. The data contained within this database is complex and beyond the scope of this article.