From: Norgg <xennocide@...>
Date: 2006-09-22T05:00:10+09:00
Subject: Re: Calculate last day of month

Gavin Kistner wrote:
>> How do I return the date for the last day of this month (September in 
>> this example)?
> 
> The last day in a month is the day before the first day in the next
> month.
> 
> require 'date'
> d = Date.new( 2006, 10, 1 )
> puts d-1
> #=> 2006-09-30
> 

Slightly nicer is:
puts Date.new(2006, 9, -1)
#2006-09-30