17th May, 1990 would be XVII. V. MCMCX in Roman numerals.
In today's notation of Roman numerals: X-XIV-MCMXC
August 6th, 1990 is written as VIII/VI/MCMXC which is 08/06/1990.
VIII-IV-MDCCCCXC
IX/VIII/MCMXC
The date 18-06-1990 in Roman numerals would be XVIII.VI.MCMXC
17th May, 1990 would be XVII. V. MCMCX in Roman numerals.
In today's notation of Roman numerals: X-XIV-MCMXC
August 6th, 1990 is written as VIII/VI/MCMXC which is 08/06/1990.
VII-VIII-MCMXC
XVIII/VIII/MCMXC
JulyIII MDDCXC
VIII-IV-MDCCCCXC
IX/VIII/MCMXC
11-27-1990 = XI-XXVII-MCMXC
7: VII 25: XXV 1990: MCMXC
"MCM" is 1990 in Roman. The rest of the date doesn't translate well as the Roman calendar is not the same as our own.