Looking at rails and the datejs library, I can't help but feel bummed that Python doesn't have an expressive and easy to use date library like that. So I started one. Here are some examples. First import it:

>>> from goodday import *

You can get today's date,

>>> today()
Date(01/24/09 12:00AM)

or what time is it now.

>>> now()
Date(01/24/09 01:01PM)

What time is it five hours from now?

>>> hours(5)._from(now())
Date(01/24/09 06:01PM)

One hour and a half from now?

>>> hour(1)._and(minutes(30))._from(now())
Date(01/24/09 02:31PM)

or equivalently:

>>> now() + hour(1) + minutes(30)
Date(01/24/09 02:31PM)

You can do the same thing with days:

>>> days(20)._from(today())
Date(02/13/09 12:00AM)

The functions second(s), minute(s), hour(s), day(s), week(s), and year(s) all return TimeInterval objects.

>>> days(20)
TimeInterval(20 days)
>>> hours(5)._and(minutes(30))
TimeInterval(5 hours and 30 minutes)
>>> day(1) + hours(4) + minutes(30)
TimeInterval(1 day 4 hours and 30 minutes)
>>> week(1)
TimeInterval(7 days)

You can use the in_words method of TimeInterval to approximate the time interval and put it in a human readable format:

>>> hours(5)._and(minutes(45)).in_words()
'about 6 hours'
>>> (day(1) + hours(4) + minutes(30)).in_words()
'1 day'
>>> years(6)._and(days(10)).in_words()
'over 6 years'
>>> (now() - now()).in_words()
'less than a minute'

You can easily format a Date:

>>> now().format()
'01/24/09 01:04PM'
>>> today().format("%m/%d/%y")
'01/24/09'
>>> now().format("%H:%M")
'13:04'

Parsing dates is done with the DateFormat object:

>>> DateFormat("%I:%M%p").parse("12:30PM")
Date(01/01/00 12:30PM)
>>> DateFormat("%m/%d/%y").parse("1/2/10")
Date(01/02/10 12:00AM)
>>> DateFormat("%m/%d/%Y").parse("1/2/1996")
Date(01/02/96 12:00AM)

You can browse the source here.