There should really be three "layers" of time indirection. 1) Seconds since 00:00:00UTC 1.1.1970. This value increases by 1 each atomic second and never goes f

There should really be three "layers" of time indirection. 1) Seconds since 00:00:00UTC 1.1.1970. This value increases by 1 each atomic second and never goes forward/back. Call this Universal Monotonic Time. 2) The difference between when the sun is at its zenith at Greenwich and 12:00 UMT. Call this the Astronomic Drift. 3) The timezone - offset from Greenwich that makes the local clock sync up with astronomic time and also contains a DST offset if that location observes DST at that date. By adding up 1) + 2) + 3) you end up with the "human time" at a given location at a given date. A computer system should only ever store 1). Then, it can calculate human time when displaying it to humans. I'm also a fan of having "local sun time" which would be the time according to the position of the sun in the sky, quantised to 15-minute slices (basically micro-timezones). It would be nice if office hours, school times, &c can be defined based on that, i.e. work starts at 9am local sun time, which will sync up better with people's biological clock and cut down on the yearly stress DST causes.