Hi all,

I've developed an interactive utility that can assist in the development of 
custom datetime format specifier strings. In addition to enumerating the 
options it will show how a combined set of options can be rendered. I plan 
on fleshing out the series to the other format specifier permutations as 
well, but this one was the toughest nut to crack so I did it first. It took 
a lot of time to develop and I feel pretty good about it as a reference; 
there is no way that I could retain the knowledge MMM is the three letter 
version of the month ;-)

http://www.nicecleanexample.com/Tools/DTCustomFmtSpec.aspx

John