Re:Let’s Stop the Unix Time Insanity
by haberman on Wednesday December 04, 2013 @02:12PM
(#6849314)
> The time used for "Unix Time" is actually UTC
Unix Time is not UTC; it is a linear representation that is surjective onto UTC. It is easy to map between the two but they are not the same. They are not even isomorphic or bijective because leap seconds have no unique representation in Unix Time.
The Unix Time representation gives up full equivalence with UTC in order to provide some useful guarantees (days are always exactly 86,400 seconds long, midnight always satisfies x % 86,400 == 0, etc), but also creates other surprises (time can go backwards when a leap second occurs).
Unix Time is not UTC; it is a linear representation that is surjective onto UTC. It is easy to map between the two but they are not the same. They are not even isomorphic or bijective because leap seconds have no unique representation in Unix Time.
The Unix Time representation gives up full equivalence with UTC in order to provide some useful guarantees (days are always exactly 86,400 seconds long, midnight always satisfies x % 86,400 == 0, etc), but also creates other surprises (time can go backwards when a leap second occurs).