On 7/28/2026 3:23 PM, Brooks Harris via tz wrote:
Well, you're seeing my concern, partly, it seems. In principle it shouldn't be a big deal. But I wonder if it isn't a good enough excuse for exploitive actors to manufacture disputes.
The 1918 standard was "The standard time of the first zone hall be based on the mean astronomical time of the seventy-fifth degree of longitude west from Greenwich;" and so forth across the five zones that existed at that time. That lasted until 2007 when it was changed to "the standard time of the first zone shall be Coordinated Universal Time retarded by 4 hours;" and so forth across the nine current zones. They have been reference times for years with the 6th, 7th and 8th zones being added for Alaska and Hawaii in 1966, those three zones modified in 1983 to unify most of Alaska into their easternmost time zone and a 9th zone for Guam added in 2000.
Any concern over contract expiration for those changes? Your contract would need to specify a time (not just a date) in a specific zone. Any "local time" contracts would have been affected by the multiple time zone changes in various locations. Not to mention the changes in the effective date of national DST in 1987 and 2007. Had a contract that expired in the weeks added to DST? You got an extra hour!
BTW: I did get an expired plate ticket between midnight and 1am on a plate that may not have been considered expired if the state was on EST instead of EDT.
Most of the contracts I have agreed to expire on a date. If midnight matters I have to be ready. But I have managed to survive many time changes.
But, I agree, it's a peripheral issue. I think the bigger problem is the technical complexity we are discussing.
True. That is why it is good that this massive test is underway. Downstream programmers relying on tzData take note and test!
The redefinition of standard time may not happen this year or next, but it is good to be ready.
