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How to Think About Time in Programming

(shanrauf.com)
189 points rmason | 3 comments | 24 Jun 25 20:01 UTC | HN request time: 0.023s | source
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zokier ◴[24 Jun 25 22:11 UTC] No.44371602[source]▶
It is a pet peeve of mine, but any statement that implies that Unix time is a count of seconds since epoch is annoyingly misleading and perpetuates such misconception. Imho better mental model for Unix time is that has two parts, days since epoch * 86400, and seconds since midnight, which get added together.
replies(2): >>44371952 #>>44374623 #
1. charcircuit ◴[24 Jun 25 22:58 UTC] No.44371952[source]▶
How is it misleading? The source code of UNIX literally has time as a variable of seconds that increments every second.
replies(1): >>44372426 #
2. adgjlsfhk1 ◴[25 Jun 25 00:13 UTC] No.44372426[source]▶
leap seconds
replies(1): >>44372901 #
3. LegionMammal978 ◴[25 Jun 25 01:34 UTC] No.44372901[source]▶
Also, UTC had a different clock rate than TAI prior to 1972. And TAI itself had its reference altitude adjusted to sea level in 1977.