The date July 4, 1991 would be written:
In English: IV July MCMXCI
In Latin: Dies Iovis IV Julius MCMXCI
In Classic Roman: DIES IOVIS A.D. XI KAL. IVL. MMDCCXLIV A. U. C.
The year 1991 is MCMXCI.
Improved answer:
In today's modern terms it is simply: July-IV-MCMXCI
The month of July was named after Julius Caesar who introduced an extra two months to the old Roman calendar which originally had only ten months and December used to be the tenth and final month of the year.
July 27, 1991, in Roman numerals is written as XXVII.VII.MCMXCI.
July 9, 1991 in roman numerals is written as VII-IX-MCMXCI.
July 19, 2008 in Roman numerals is written as XIX.VII.MMVIII.
The date July 7th 1989 can also be written as 07-07-1989 and in Roman numerals this can be written as VII.VII.MCMLXXXIX
July 2nd 1999 can also be written as 07-02-1999 and in Roman numerals this could be written as VIII.II.MCMXCIX.
July 27, 1991, in Roman numerals is written as XXVII.VII.MCMXCI.
July 9, 1991 in roman numerals is written as VII-IX-MCMXCI.
July 19, 2008 in Roman numerals is written as XIX.VII.MMVIII.
July 2nd 1999 can also be written as 07-02-1999 and in Roman numerals this could be written as VIII.II.MCMXCIX.
The date July 7th 1989 can also be written as 07-07-1989 and in Roman numerals this can be written as VII.VII.MCMLXXXIX
7-23-1991 = VII-XXIII-MCMXCI
Roman numerals represent numbers, not months. However, July is the seventh month, and if you want to write "7" as a Roman numeral, it is VII.
July, IV, MDCCLXXVI
14th July 1966 can also be written as 14-07-1966 which can be represented by the Roman numerals XIV.VII.MCMLXVI.
July 17, 2008 in Roman numerals is written as XVII-VII-MMVIII.
July 31, 2010 is written as XXXI.VII.MMX in Roman numerals.
July 14th in roman numerals would be: VII/XIV