time axis syntax error

[dbess@xxxxxxxxxxxxxxxxxxxx (T D Bess)]

I'm trying to create a netCDF file from monthly time
series data over multiple years. I keep getting this 
syntax error
	command syntax: 1-jan-88:12:00
	def axis/t="1-jan-88:12:00":"31-dec-88:12:00":12/units=months tax1
	command file, command group, or REPEAT execution aborted.

Anyone know what I'm doing wrong?

Dale bess