Re: [Haskell-cafe] Parsing LocalTime from Unix seconds

On Mon, Sep 17, 2018 at 09:12:38AM -0400, Viktor Dukhovni wrote:

...

On Sep 17, 2018, at 2:01 AM, Tobias Dammers wrote:

Also, unix time may represent either actual seconds elapsed since epoch, or "logical" seconds since epoch (ignoring leap seconds, such that midnight is always a multiple of 86400 seconds).

That would be a violation of the specification:

http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_...

Ah yes, you are right. Problem is, while Unix systems to day use Unix time this way, not all other software systems do, or they may assume that "current unix timestamp - some unix timestamp in the past = exact number of seconds elapsed between timestamps". Which doesn't hold in the presence of leap seconds, no matter how you implement them. In other words, people use Unix timestamps (both the word and actual implementations) sloppily.