Subject: Re: How to get arbitrary time in shell script?
To: Christoph Kaegi <kgc@zhwin.ch>
From: Jeremy C. Reed <reed@reedmedia.net>
List: netbsd-users
Date: 11/28/2001 13:51:04 
On Wed, 28 Nov 2001, Christoph Kaegi wrote:

> So, how can i get a date from three days ago?
> date(1) doesn't have an option like 
> 
>    date '+ 3 days ago'

 date -r `expr \`date +%s\` - 259200`
# where 259200 is 60 seconds * 60 minutes * 24 hours * 3 days

Then add +%whatever for the format you want; see strftime(3).

   Jeremy C. Reed
   http://www.reedmedia.net/