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From: vogt@iuvax.cs.indiana.edu (Michael Vogt)
Newsgroups: comp.databases,comp.software-eng,comp.infosystems
Subject: Time Zones HELP!
Message-ID: <1991Apr5.103756.18982@news.cs.indiana.edu>
Date: 5 Apr 91 15:37:45 GMT
Organization: Computer Science, Indiana University, Bloomington.
Lines: 32

Hi,

I'm hoping you can help us with a design problem we have come across.

What date/time format do people use when dealing with data
that crosses date and time zones?  How are time changes like daylight
savings time and standard time dealt with?  

How do distributed databases handle date/time if the databases are
located in different zones?

How do flight/navigation/distribution systems handle different
date/time zones?


Our specific problem is this:  We receive laboratory specimens from
across the world.  We record the date and time of the specimen draw
(as recorded at the location of the draw).  We also record our time
of receipt (as specified by our location).  We need to be able to
calculate the number of hours between the draw and our receipt so that
we will know if the specimen's stability has expired.

Now the constraints:  We don't want to ask for zone, (indeed we don't
know if all locations have unique identifiers for time zones (i.e.
EST)).  We will know the location of the specimen draw.


ANY help/insight is appreciated!

Thanks
-Mike
My preferred address is vogt@fermat.mayo.edu