FW: 64-bit time_t and tz file format

Olson, Arthur David (NCI) olsona at dc37a.nci.nih.gov
Thu Jun 10 17:29:57 UTC 1999

-----Original Message-----
From:	alan perry [SMTP:esprit at jps.net]
Sent:	Thursday, June 10, 1999 1:18 PM
To:	tz at elsie.nci.nih.gov
Subject:	64-bit time_t and tz file format

A couple of days ago, I posted something to this list about how to
go about changing the tz file format to support a 64-bit time_t
value.  I have heard nothing back.

I was looking through the tzcode to see if this problem has been
addressed already and found the following comment in the zic source.

> ** The tz file format currently allows at most 32-bit quantities.
> ** This restriction should be removed before signed 32-bit values
> ** wrap around in 2038, but unfortunately this will require a
> ** change to the tz file format.

So, has anyone been looking into this issue?

As I noted earlier, the current tz file format doesn't scale
well to a 64-bit time_t and all of the possible additional timezone
transitions that result from the addition years that can be

As OS vendors (including the one that I used to work for) consider
what to do with time_t when their OS adds 64-bit support and how
to deal with 2038, they might be tempted to come up with their own
solution if it doesn't get addressed by the elsie code.


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