Decoding CRONTAB

[Peter Hkansson]

the
small
green
line-
eater:
(mums
mums
mums)
	I am involved in building a scoolplanning system where it is
convinient to express 'preferrable times' something can occur.
Looking at the way CRON expresses this i found this would be OK for
us.
	However, to decode those strings seems tricky, maybe someone
has done it before me (it is certenly done in crontab) and is willing
to share it with me ? 
	Otherwize hints would be appreciated.
(sorry about the spelling, the phone lines does not like winter).