From: "David A. Black" <dblack@...>
Date: 2009-09-22T06:10:03+09:00
Subject: Re: find the number of hours in a day

Hi --

On Tue, 22 Sep 2009, Nick Brown wrote:

> I'm trying to determine the best way to find the number of hours (or
> seconds) in a given day in a given timezone. Is there a "right" way to
> do this with Ruby?
>
> There are so many ways to deal with dates and times in Ruby (Time, date,
> datetime, ActiveSupport:...:Time, Chronic, ActionView) that I almost
> don't know where to start.
>
> Basically, if there are 25 or 23 hours in a day due to daylight savings,
> I need to know so that I can handle that special case. How would you
> handle this?

I suspect there's a better way, probably already in a library
somewhere, but what occurs to me in the absence of knowing where is:

def seconds(day)
   Integer(day.tomorrow.midnight - day.midnight)
end

def hours(day)
   seconds(day) / 3600
end

(using ActiveSupport). I guess the Integer part might clash with leap
seconds, but you get the idea.


David

-- 
David A. Black, Director
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Book: The Well-Grounded Rubyist (http://www.manning.com/black2)