On 2025-01-27 21:01:59 +0000, Nem Tudom wrote: > I'm having trouble understanding matters related to TIMESTAMP(TZ)-s and leap > seconds - my machine runs on UTC so as to remove any issues related to the > zones. > > From here: https://en.wikipedia.org/wiki/Leap_second, > > There have been 27 leap seconds added to UTC since 1972. > > > But, when I run this fiddle (see bottom of this email link) > > https://dbfiddle.uk/wxvmzfJb > > (first snippet - 2015 -> 2016) I get a "nice" even number for the EPOCH of, > 00:00:00 2016 , say (= 1451606400) - now, with 27 leap seconds since 1972, I > would expect that number to be (something like) 1451606427? > > I thought that the EPOCH was the number of seconds since 1970-01-01 > 00:00:00? Is this incorrect? The POSIX standard mandates that leap seconds must be ignored. It's not really "number of seconds since 1970-01-01", but "number of days since 1970-01-01 times 86400 plus number of seconds in the current day". So you can't use epoch to detect leap seconds. And I don't think PostgreSQL keeps track of leap seconds internally either, so that information simply isn't there to begin with. hp -- _ | Peter J. Holzer | Story must make more sense than reality. |_|_) | | | | | hjp@xxxxxx | -- Charles Stross, "Creative writing __/ | http://www.hjp.at/ | challenge!"
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