From: "Peña, Botp" <botp@...>
Date: 2008-11-27T16:55:20+09:00
Subject: Re: unexpected error in time difference

From: Heesob Park [mailto:phasis@gmail.com] 
#--
# irb(main):002:0> Time.now -1
# ArgumentError: wrong number of arguments (1 for 0)
#         from (irb):2:in `initialize'
#         from (irb):2:in `now'
#         from (irb):2
#...
# irb(main):006:0> Time.now -t
# NoMethodError: undefined method `-@' for Thu Nov 27 16:19:48 
# +0900 2008:Time
#         from (irb):6
#         from :0

fwiw, i like the dot for its power, emphasis, and lesser surprise.

> Time.now .- 1
=> Fri Nov 28 00:03:38 +0800 2008
> Time.now .-1
=> Fri Nov 28 00:03:57 +0800 2008
> Time.now.-1
=> Fri Nov 28 00:04:00 +0800 2008

> t=Time.now
=> Fri Nov 28 00:09:15 +0800 2008
> -t
NoMethodError: undefined method `-@' for Fri Nov 28 00:09:15 +0800 2008:Time
        from (irb):20
        from :0
> Time.now -t
NoMethodError: undefined method `-@' for Fri Nov 28 00:09:15 +0800 2008:Time
        from (irb):21
        from :0

> Time.now. -t
=> 18.928238