I don't know how Romans would have written dates of birth but written the same way as you have, it would be:
XI I MCMLXXXIII
In today's terms it is: X-XXI-MCMLXXXIII
The date of birth 19101989 in Roman numerals is XIX.X.MCMXCIX.
The date of birth 05041971 in Roman numerals is V.IV.MCMLXXI.
XII/I/MCMLXXXIII Is December 1st 1983, XII is twelve, I is one, and MCMLXXXIII is 1983
The date 03.04.1989 is written in roman numerals as III.IV.MCMLXXXIX
XXVII-IV-MCMLXXXIII
XII-XVIII-MCMLXXXIII
In today's terms of expressing Roman numerals: X-XXI-MCMLXXXIII
25 = XXV 09 = IX 1983 = MCMLXXXIII
In today's terms it is: X-XXI-MCMLXXXIII
The date of birth 19101989 in Roman numerals is XIX.X.MCMXCIX.
The date of birth 05041971 in Roman numerals is V.IV.MCMLXXI.
XII/I/MCMLXXXIII Is December 1st 1983, XII is twelve, I is one, and MCMLXXXIII is 1983
Under today's rules: XXIX-III-MCMLXXXIII
The date 03.04.1989 is written in roman numerals as III.IV.MCMLXXXIX
The date of birth 12-02-2009 in Roman numerals would be XII.II.MMIX
The date of birth 07072001 in Roman numerals is VII VII MMCI.