I've followed the discussions about historical data with interest. I would like to keep historical data in the tzdb, and I understand why I'm in the minority. But I wonder if there couldn't be a compromise? We've implemented a .NET library that uses the tzdb by interpreting[1] the database rather than by compiling it. So for us, we only deploy the tzdb text files that the customer cares about. Some customers are strictly North American concerns, so we only put the northamerica file in their configuration; others need the whole database of 500-some zones. I think other posters have suggested separating pre-1970 data out into a separate file or file set. This would be perfect for our implementation. For the zic implementation, it seems like compilation is an all-or-nothing deal right now. But would it be difficult to create a build script that includes the historical data to the zic package if someone needs it, in addition to the post-1970 build script? Sorry if the question seems naïve. I just think there's room to compromise here. David Braverman Inner Drive Technology Chicago [1] The tzdb files actually get compiled down to an intermediate set of objects at application start, then live on in a singleton. The process takes about a second on an Azure Extra-Small instance. More info here: https://www.inner-drive.com/Demo/Timezones.aspx