III XI MCMXCI
I assume.
X-XXI-MCMXCI
June 21, 2008 in roman numerals is written as XXI.VI.MMVIII.
XXIXXI = 21
May 21, 1995 in roman numerals is written as XXI V MCMLXXXV.
December 21, 2011 is written as "XII XXI MMXI" in Roman numerals.
September 21, 2013 can be written in Roman numerals as "XXI-IX-MMXIII".
The date February 21st 2009 can also be written as 02-21-2009 and in Roman numerals this would be II.XXI.MMIX
XXI is the number 21 in Roman numerals.
In today's notation: XI-XXI-MCMXCI
21 in Roman numerals is XXI. 1 in Roman numerals is I. 90 in Roman numerals is XC. So, 21 1 90 would be XXI I XC in Roman numerals.
The date 21-11-2007 in Roman numerals would be XXI.XI.MMVII
10 21 1986 in roman numerals: X XXI MCMLXXXVI