From: Ross Bamford <rossrt@...>
Date: 2006-04-23T21:39:48+09:00
Subject: Re: How to make an array from a date range?

On Sun, 2006-04-23 at 20:58 +0900, Marston A. wrote:
> What is the easiest way in Ruby to make an array our of a date range? 
> Something like this:
> 
> @date1 = "2006-04-01"
> @date2 = "2006-04-23"
> 
> array = [@date1..@date2]
> 
> Something like that would be an easy solution as @date1 and @date2 are 
> going to by dynamic, but this doesn't work as they are strings.
> 
> Or would I have to manually insert the ranges one by one myself?
> 
> array = ["2006-04-01", "2006-04-02", ... , "2006-04-23"]
> 
> Thanks for any help in advanced!
> 

I don't know if this is the easiest (or best) way, but it seems to work:

require 'date'			# from stdlib
# => true

(Date.parse('2006-04-01')..Date.parse('2006-04-23')).to_a.map { |e| e.to_s }
# => ["2006-04-01", 
      "2006-04-02", 
      "2006-04-03", 
      "2006-04-04",
      ...,
      "2006-04-23"]


You can do a similar thing with Time to get different ranges (hours,
half-days, etc.) but it's pretty wasteful in terms of efficiency so
stick with date if you can.

a = []
# => []

(Time.parse('2006-4-23')..Time.parse('2006-4-27')).step(86400) { |t| a << t }
# => Sun Apr 23 00:00:00 BST 2006..Thu Apr 27 00:00:00 BST 2006

a
# => [Sun Apr 23 00:00:00 BST 2006, 
#     Mon Apr 24 00:00:00 BST 2006, 
#     Tue Apr 25 00:00:00 BST 2006, 
#     Wed Apr 26 00:00:00 BST 2006, 
#     Thu Apr 27 00:00:00 BST 2006]

a = []
# => []

(Time.parse('2006-4-23')..Time.parse('2006-4-27')).step(3600) { |t| a << t }
# => Sun Apr 23 00:00:00 BST 2006..Thu Apr 27 00:00:00 BST 2006

a
# => [Sun Apr 23 00:00:00 BST 2006, 
#     Sun Apr 23 01:00:00 BST 2006, 
#     Sun Apr 23 02:00:00 BST 2006, 
#     Sun Apr 23 03:00:00 BST 2006, 
#     Sun Apr 23 04:00:00 BST 2006, 
#     Sun Apr 23 05:00:00 BST 2006, 
#     ... 97 elements ... ]

-- 
Ross Bamford - rosco@roscopeco.REMOVE.co.uk