January is the first month so I. 11 is XI and 2011 is MMXI. It would be written:
I XI MMXI
January would be represented with an I. You would write it as I-XI.
I-XI-MCMXCVI
It is: XI-VII-MMXII
November 11th 2009 can also be written as 11-11-2009 which is written in Roman numerals as XI.XI.MMIX
To convert January 11, 2009 into roman numerals, you can break it down into separate numbers and convert them individually. January is the first month, so it is represented by "I". 11 is represented by "XI". Finally, 2009 is represented by "MMIX". Putting it all together, January 11, 2009 in roman numerals is "I XI MMIX".
Today's conventional conversion of 11th September 2009 into Roman numerals is XI-September-MMIX whether or not the Romans themselves did it this way is questionable.
II-XI-MMIX
It is: X-XI-MMI
It is: XI-XI-MMXIII
It is: X-XI-MMXI
VII-XI-MCMXLIV
The conventional conversion of 11th September 1998 into Roman numerals is XI-September-MCMXCVIII whether or not the Romans themselves enumerated it in this way is questionable.