From: Christopher Thompson <cthompson@...>
Date: 2009-01-21T04:34:17+09:00
Subject: [ruby-core:21475] Re: Time.gm give me ArgumentError out of range (ruby 1.8.6 (2007-09-24  patchlevel 111) [i486-linux])

Claudio Fiorini wrote:
> Hi all,
> today i was fetching some data from a database through odbc and during
> mapping of types i got argument error 'out of range'.
> To repeat this error i have created a new file, very simple, with this:
> 
> puts Time.gm(2009,1,1)
> puts Time.gm(1800,1,1)
> 
> and this is the result:
> 
> prova.rb:2:in `gm': time out of range (ArgumentError)
> 	from prova.rb:2
> 
> I found out that the first year that doesn't return error is 1902.
> Digging in file time.c i read about the tmcmp function, but i couldn't
> understand why, can someone explain me please?
> 
> Thanks a lot
> 
> Claudio


See http://www.ruby-doc.org/core/classes/Time.html#M000250

Time is stored internally as the number of seconds from the epoch.  On
some platforms/implementations, you are permitted to use negative
numbers.  That limits you to +/- 2^31 seconds from the epoch (Jan 1,
1970).  In fact, you can create times in 1901 on most platforms, just
not as far back as Jan 1, 1901.