It is: X-XXX-IX because X = 10, 30 = XXX and 09 = IX
XXIV/IX/MCMXXIV
XVIII-IX-MCMXC
25 = XXV 09 = IX 1983 = MCMLXXXIII
The date 9-9-09 in Roman numerals is IX.IX.IX. If the numbers represent the date 09-09-2009 that would be IX.IX.MMIX
The date 09-28-1979 in Roman numerals would be IX.XXVIII.MCMLXXIX
The date 03-09-2000 in Roman numerals would be III.IX.MM
I am assuming that you mean the date 09-09-07, in Roman numerals this would be IX.IX.VII and the full version of the date 09-09-2007 would be IX.IX.MMVII
The date 09-08-85 in Roman numerals would be IX.VIII.LXXXV and the full version of the date 09-08-1985 would be IX.VIII.MCMLXXXV
The date 12-09-1988 in Roman numerals would be XII.IX.MCMLXXXVIII
The date 09-27-1988 can be written in Roman numerals as IX.XXVII.MCMLXXXVIII
The date 09-11-06 can be written in Roman numerals as IX.XI.VI. The full date 09-11-2006 would be IX.XI.MMVI
The date 09-27-1988 can be written in Roman numerals as IX.XXVII.MCMLXXXVIII