From: Kirk Haines <khaines@...>
Date: 2005-11-15T04:19:43+09:00
Subject: Re: Time out of range when selecting from database?

On Monday 14 November 2005 11:16 am, Ron M wrote:
> Why does Time allow such a limited set of years:
>
>     irb> Time.mktime('2205-01-01')
>     ArgumentError: time out of range
>
> This especially annoying when other classes like DBI use
> the Time class, and when a 200-year-lease in a database
> throws an exception when loaded by Ruby.

See the discussion about converting between Time and DateTime.  Time uses 
seconds since the start of 1970, and basically just uses the underlying C 
functions for most of what it does.  So, you are pretty limited in your date 
range.  Within the range supported, Time is fast because it uses a simple 
unit and C functions underneath, but that loses flexibility.

DateTime uses the Rational class, and can handle whatever date you want to 
give it.  It is a lot slower than Time, though.

Now, for DBI, there are a few issues with DBI currently with regard to dates.  
One of them is what you are describing.  DBI actually stores dates internally 
in one of three different classes, and internally it stores years, months, 
dates, hours, minutes, seconds separately, so it'll support any date that you 
want.  But the code that creates a DBI::Timestamp for you uses the Time 
class, which is where your error came from.

A patch for DBI to to deal with this gracefully looks like it should not be 
too hard, though.  I'll see if I can whip one up sometime in the next day or 
two.


Kirk Haines