[tz] tzcode-2014c breaks applications that use the binary tz files

Paul Eggert eggert at cs.ucla.edu
Fri May 23 21:10:58 UTC 2014

On 05/23/2014 01:51 PM, Arthur David Olson wrote:
> Do we face a similar challenge in the 32-bit realm?

Not for Glib, no.  It uses 64-bit signed integers internally.

If this were a problem in the 32-bit realm, wouldn't we have already run 
into it?  Some of tzdata's transitions are before 1901 and thus predate 
the 32-bit window, so I assume that for many years we've been 
approximating them with a transition at -2**31 -- is my assumption 

One other thought, just for fun.  In the 64-bit realm, we could use the 
timestamp of the Big Bang, as time stamps before then are physically 
suspect anyway.  If we use POSIX time, our current best guess is that 
the Big Bang happened 13.82 billion years ago, which (if we use the 
POSIX origin of 1970) would make it -13,820,000,000 * 365.2425 * 86400, 
or -436117076640000000 -- a 59-bit number.  A downside of using 
-436117076640000000 is that we'd need to update that number as we get 
better estimates of when the Big Bang occurred, but maybe we could 
consider this to be part of the fun.  After all, if Unix had been 
developed on a 64-bit machine and had used the Big Bang for the time_t 
origin, a lot of bugs would have been avoided in the first place....

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