From: Gregory Seidman <gsslist+ruby@...>
Date: 2008-02-28T01:40:02+09:00
Subject: Re: Getting number of days in a month

On Thu, Feb 28, 2008 at 01:17:22AM +0900, Shandy Nantz wrote:
> This is probably an easy question but I am trying to get at the number
> of days that are in a month. I have this calendar that I have built, the
> idea being that when a month turns from February to March, for example,
> the calendar should redisplay itself properly formated showing the new
> month and the correct number of days. I have it so that it starts
> counting the days on the right day of the week, but I have to know when
> to stop counting. Any ideas, Thanks,

require 'date'

def days_in_month(month, year)
  month = month.to_i
  year = year.to_i
  raise ArgumentError.new("invalid month") unless (1..12).to_a.include? month
  first = Date.parse sprintf("%04d%02d01", year, month)
  next_month = first + 32
  (last - last.mday).mday
end

> -S
--Greg