I have to say these time zone files are fascinating. Any place/time when a jurisdiction has changed the definition of time is in those files, along with a detai

I have to say these time zone files are fascinating. Any place/time when a jurisdiction has changed the definition of time is in those files, along with a detailed history of why. Example, California had an energy crisis soon after WWII, and changed when day light savings started/ended. There are time zone rules that track this history exactly, including a note about how clocks lost 6 minutes a day because PG&E changed AC from 60 to 59.5 Hz: https://github.com/eggert/tz/blob/71faa2a55db2c9f21f4099b58c28536673982e0a/northamerica#L517 https://github.com/eggert/tz/blob/71faa2a55db2c9f21f4099b58c...