The latest short-notice time zone change from Egypt, so soon after the Mexico changes, made me wonder... Would it be useful to have a canonical thread or set of links in the TZDB docs to point to for user-facing "Why hasn't my device updated?" or government-facing "Why didn't our legislation change reach citizen's devices in time?" -type questions? For example, here are recommendations/policy I know of for a couple of widely-used operating systems / platforms: Android: https://source.android.com/docs/core/connect/time/time-zone-policy-recommend... (this is relatively new) Windows: https://learn.microsoft.com/en-us/troubleshoot/windows-client/system-managem... Maybe these could be collated and extended for other consumers of TZDB. ------- I vaguely remembered there being something in the TZDB docs that says something along these lines [*] but I couldn't find it and might be getting confused with threads on the mailing list. I don't honestly expect having it written down to make a lot of difference, but the regular lack of notice and confusion about what *exactly* governments have changed makes me think there *could* be a set of recommendations. Then, governments that *want* to do the right thing could then know what to provide / expect and plan accordingly, and ones that don't try can be easily informed why things didn't work out like they may have expected. Thanks, Neil. [*] e.g. maybe something like "Many downstream users of the TZDB wait for an official TZDB release before they will produce an update to time zone behavior in consumer devices and software products. After TZDB has been updated, various parties have to perform their own integration, testing, and rollout of an update before users will see changes. These updates can be expensive, e.g. for the QA process itself and the network costs for updates to each TZDB copy. Updates may be batched with other updates and take substantial time to reach users after the TZDB release. Updates will require that affected products have a suitable update mechanism in place and are still supported." -- Google UK Limited Registered Office: 6 Pancras Square, London, N1C 4AG Registered in England Number: 3977902