[NTG-context] month form \currentdate in Roman numerals

Dear list, I would like to get the current month in Roman numerals (just now, it would be XII for December). The best I get is: \currentdate[\cldcontext{converters['R'] (tonumber(os.date("\letterpercent m", os.date(os.time()))))}] This strikes me as too complex (even for someone who cannot code). Is there now simpler way to write that? Just in case it may be relevant, this is part of the full day reference. Many thanks for your help, Pablo