From: Peter Simons [mailto:simons@cryp.to]
Well, there _is_ an absolute notion of time, that is what TAI is. The reason why that seems to be of little use for the general public is that this absolute time scale just doesn't correspond to calendar time. There simply is no accurate mapping between TAI and the information 2043-04-01T00:00:00.
I assume that the only reason we can't establish a mapping between 2043-04-01T00:00:00 and TAI is because of the leap seconds problem. I assume we can map accurately between TAI and (say) 2001-01-01T00:00:00 (Gregorian). And I assume that we just accept that the TAI <-> UTC/Gregorian/whatever mapping cannot be accurate for times in the future. My point was that when you say "here is a time, specified as x", where x is one of TAI / UTC / Julian+TZ / Gregorian+TZ / etc, any of the x's is as good as any other (as long as the time is not in the future), and the internal representation of time could be any one of, or none of x. I think people are proposing TAI as an internal representation, but it's not necessary, and I'm wondering if it's even desirable. What are the limits on a 64bit TAI implementation? 64 bits gives you (signed integers): +/- 9223372036854775807: Assuming milliseconds (is this reasonable?): 922337203685477.5807 secs ~= 106751991167 days ~= 292471208 years OK, that seems plenty... ----------------------------------------- ***************************************************************** Confidentiality Note: The information contained in this message, and any attachments, may contain confidential and/or privileged material. It is intended solely for the person(s) or entity to which it is addressed. Any review, retransmission, dissemination, or taking of any action in reliance upon this information by persons or entities other than the intended recipient(s) is prohibited. If you received this in error, please contact the sender and delete the material from any computer. *****************************************************************