Date math lib?

ruby-talk
1

Generally speaking, Time, Date and ParseDate can accomplish all of your
date-time calculation needs.

For your example, here’s one solution (there may be a better one):

years_to_subtract = 34
d1 = Date.new(2003,1,29)
d1.year → 2003
d2 = d1 << (years_to_subtract * 12)
d2.year → 1969

The << method subtracts months (hence the *12). I don’t know of a way to
subtract years.

On another note, I noticed something wonky with ParseDate in Windows
(1.6.7):

require “parsedate”
x = Time.now
a = ParseDate.parsedate(“#{x}”).slice(0…5)

In *nix, a[0] is 2003
In Windows, however, I get nil.

Any ideas anyone?

Regards,

Dan

···

-----Original Message-----
From: Chris Morris [mailto:chrismo@clabs.org]
Sent: Wednesday, January 29, 2003 10:25 AM
To: ruby-talk@ruby-lang.org
Subject: Date math lib?

I’m in need of some date math routines – primarily a way to
add/subtract years from a date, which appears to be more than
just a no-brainer routine to do it Right™ (or maybe my
brain is in over-complication mode). Searching RAA and the
archives didn’t come up with much.

Chris
http://clabs.org

2

Generally speaking, Time, Date and ParseDate can accomplish all of your
date-time calculation needs.

Huh. I guess Date’s thin little entry in the Pickaxe book has escaped my
attention all this time. Sorry for the noise. Thanks, Dan.

Chris