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A comment on Australia/Lord_Howe is the weirdest timezone.

Re:Australia/Lord_Howe is the weirdest timezone by fouronnes3 on Wednesday October 30, 2024 @03:54AM (#41992724)
What I like about the tz database is that's it's technically a diff of a diff. It stores the difference across history, of the difference of each timezone with UTC. Right? So it's a diff^2. But! The tz database gets updates! So those commits are diffs of diffs of diffs, or diff^3.

Can we go further? You bet! It has a changelog, and that changelog is stored in git, so commits to the tz changelog are diff^4: they are changes to the list of changes to the list of changes to the list of changes to UTC.

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Re:Australia/Lord_Howe is the weirdest timezone by dalmo3 on Wednesday October 30, 2024 @05:35AM (#41993236)
You forgot that UTC (or timekeeping in general) itself is a diff.
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Re:Australia/Lord_Howe is the weirdest timezone by fouronnes3 on Wednesday October 30, 2024 @07:28AM (#41993750)
Oh that's a great point! We have achieved diff^5 at last!

Now that I think of it, we could even stretch it one more level. In practice UTC is "realized" as a "best of" diff to atomic clocks in labs around the world, which are themselves diff against a fixed time point, as you pointed out. So that realization technically changes when the official UTC bulletin[1] is published by BIPM. So diff^6!

[1] https://www.bipm.org/en/time-metrology

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Re:Australia/Lord_Howe is the weirdest timezone by hhdhdbdb on Wednesday October 30, 2024 @07:58AM (#41993934)
Can we bring relativity in for another diff :)
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Re:Australia/Lord_Howe is the weirdest timezone by flippyhead on Wednesday October 30, 2024 @08:42AM (#41994208)
Yes, but, it's always 5 o'clock somewhere, amiriiight??
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Re:Australia/Lord_Howe is the weirdest timezone by Yossarrian22 on Wednesday October 30, 2024 @09:12AM (#41994413)
Don’t forget using GPS to get the time and tell you if you’ve crossed time zones
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Re:Australia/Lord_Howe is the weirdest timezone by gavindean90 on Wednesday October 30, 2024 @11:48AM (#41996445)
So would that be diff ^ 10?
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Re:Australia/Lord_Howe is the weirdest timezone by Horffupolde on Wednesday October 30, 2024 @08:23AM (#41994086)
A diff of a diff is just 2 diff. It’s not a product of diffs.
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Re:Australia/Lord_Howe is the weirdest timezone by ninalanyon on Wednesday October 30, 2024 @09:30AM (#41994543)
Spoilsport!
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Re:Australia/Lord_Howe is the weirdest timezone by Horffupolde on Wednesday October 30, 2024 @10:26AM (#41995278)
Just be rigorous with your words.
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