XVII/V/MCMXCI
May 17th, 2011 in roman numerals would be: V/XVII/MMXI.
17th May, 1990 would be XVII. V. MCMCX in Roman numerals.
July XXVII MDCCCCLXXXXI or July XXVII XMMI. Note that 1991 in Roman numerals is not MCMXCI as you may have been led to believe.
Today's modern way of converting May 23 1991 into Roman numerals is May-XXIII-MCMXCI. But the Romans themselves in times gone by would have probably wrote out 1991 as MDCCCCLXXXXI.
II-V-MCMXCI
May is the fifth month and would be V. The 17th is represented by XVII. And the year would be MCMXCI. So it would normally be shown as V-XVII-MCMXCI.
In today's notation of Roman numerals it is: V-MCMLXXIV
In today's notation of Roman numerals: V-III-MCMXXVI
May 6, 2011 in Roman numerals is V VI MMXI
May 1, 2010 in Roman numerals is written as V.I.MMX.
May 15, 2010 is written as XV.V.MMX in Roman numerals.
May 8, 2002 in Roman numerals is written as VIII.V.MMII.