CONVERT BETWEEN ARABIC NUMBERS & ROMAN NUMERALS Please enter a number 1 - 4999 or a Roman numeral I - MMMMCMXCIX Roman numerals may contain M, D, C, L, X, V & I.

ROMAN NUMERAL AND
DATE CONVERSION
WITH ROMAN CALCULATOR
& ROMAN NUMERALS TEST

©MCMXCIX STEPHANUS GIBBS, SARNIA INSULÆ

There is much information on Paul Lewis's pages Roman Numerals & Dates, acknowledged with thanks.

DATE CONVERSION is the date in the Gregorian calendar; is the date in the Gregorian calendar, in Latin; is the date in the Julian calendar; is the date in the Julian calendar, in Latin; is the date in the Julian calendar, Roman style.   JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember   «--  You can enter a date in the Gregorian   or in the  Julian   calendar,   You can also use this to determine the day of the week for any Gregorian or Julian date. e.g. The Battle of Hastings, 14th. October 1066, was fought on a Saturday.

ROMAN CALCULATOR Valid input is I - MMMMCMXCIX (1-4999). Results < -4999 or > 4999, or invalid Roman input, will show error.   Press = twice to clear.   A result of zero is shown by a dot. Divisions are rounded to the nearest integer.

ROMAN NUMERALS TEST CAN YOU SCORE X OUT OF X ? Please enter the equivalent of the above numeral or number in the space below

NOTA BENE

1.   Gregorian calendar input before 15th October 1582 or after 30th January 4247 is not valid.  There was wide variation in the date of adoption of the Gregorian calendar.  For example, in Great Britain and colonies, the Julian date Wednesday 2nd September 1752 Old Style was followed the next day by the Gregorian date Thursday 14th September 1752.

2.   Julian calendar input before 1st March 4 or after 31st December 4246 is not valid.  The conversion assumes that Julian years began on 1st January, but in many countries this was not the case, with New Year's Day falling on some other date, so users should allow for this where necessary.  For example, in England the last day of 1750, Sunday 24th March 1750 Old Style was followed by the first day of 1751, Lady Day, Monday 25th March 1751 Old Style.

3.   Roman dates between A.D. XIX KAL. IAN. and PRID. KAL. IAN. (14th - 31st December) present a conundrum:  whether to state the year as the current year, or to state the year as the year to which these dates are referenced, i.e. as the year which follows on 1st January.  This conversion adopts the latter method, as detailed in Calendrical Calculations (referenced below) chapter 3.2, page 70.

4.   For further calendar information, see

   • Old Style and New Style Dates and the Change to the Gregorian Calendar, by Mike Spathaky;

   • Calendopaedia - The Encyclopaedia of Calendars, by Michael Astbury;

   • Reingold & Dershowitz, 2001, Calendrical Calculations, The Millennium Edition, Cambridge University Press, ISBN 0-521-77152-6;

   • Richards, 1998, Mapping Time, Oxford University Press, ISBN 0 19 286205 7; date conversion algorithms used here are based, with thanks, upon those given in chapter 25;

   • Blackburn & Holford-Strevens, 1999, The Oxford Companion to the Year, Oxford University Press, ISBN 0 19 214231 3.

5.   To make use of this conversion page without going on line, use your browser to SAVE [Ctrl-S] the page as a file on your hard disk, then OPEN [Ctrl-O] the disk file and BOOKMARK [Ctrl-D].

6.   I welcome links to this page; Google has a list of pages which link here.  Please do not rip off this material to your webspace.  These JavaScript routines need browser version 4 or later.  Tested using Netscape Navigator v4.79 & MS Internet Explorer v6.0.  This page validates to HTML 4.01 & CSS standards.  Please report problems to Steven Gibbs.

"Just thought you'd be interested to know I aced my test on Roman Numerals  thanks to you and your website!  In fact, they said I was the only person to get  every single one right!  So thank you!"    - Janet, pharmacy student, Anchorage, Alaska, USA.           September 2001