IV-IV-MMXI
April 4, 2011 is written as IV.IV.MMXI in Roman numerals.
2011 = MMXI
The roman numeral for April 16th, 2011 would be: IV-XVI-MMXI.
IX.VII.MMXI
IV-XXX-MMXI
Xlv
2011 = MMXI
The roman numeral for April 16th, 2011 would be: IV-XVI-MMXI.
IX.VII.MMXI
In today's notation: XXIX-IV-MMXI
IV.V.MMXI
IV-XXX-MMXI
2011 = MMXI
MMXI
Exactly as in the question but in Roman numerals: 2011 = MMXI
Xlv
MMXI
2011 = MMXI = 1000+1000+10+1 = 2011