I have a date in the following iso format:

ISODATE
2017-09-01 10:43:04.000

The format is Stata is: %tcCCYY-NN-DD_HH:MM:SS.sss

I'm trying to extract out the month but haven't been able to make it work.

I tried various forms such as:
gen month=month(ISODATE)

Appreciate some help here. thanks.