Dave, our list moderator asked some very crucial questions and hopefully my answers are clear enough for people to follow. Working in the time periods that befall our converting to the New Style calendar from the Old Style calendar for my own research - that is Mayflower passengers as well as researching my ancestors in England, I have pretty much gotten used to the dating systems that apply to most of our American ancestors because they came from England. For those of us who have ancestors who came from other countries besides England, I would suggest you find a source that explains the use of calendars that cover the time period of your research as it may be different than the one that generally applies to American research. The conversion from the Julian calendar to the Georgian calendar was applicable at different time periods, so one needs to check when it took place. First, I suggest everyone buy this book for their own personal library. It will answer in detail questions about dating and when it started in various areas around the world. Cheney, C.R., ed. HANDBOOK OF DATES FOR STUDENTS OF ENGLISH HISTORY. London: Offices of the Royal Historical Society, University College London, Gower Street, W.C.1, reprint 1991. (Originally published 1945.) This was required course work book for a class I took in genealogy at BYU several years ago. Perhaps the price of the book has gone up, but maybe not, definitely postage and handling will be increased. I paid $19 for the book and $4.30 for postage back then. I purchased the book through BYU in 1994, but it was shipped from the following company: Boydell & Brewer, Inc. P.O. Box 41026 Rochester, NY 14604 Tele: 716-275-0419 Fax: 716-271-8778 <Howdy folks - been some time since I posed a query or two, but the following questions seem to be on my mind most recent. And I would like all answers to reflect the practice here in America, and not necessarily what may have been practiced in England and Europe or elsewhere: <1. What is the time period of the O.S. (old dating system) and when did the current one we use, begin? Umm, were there more than one 'old system'? > Here in the US and also in England, we switched calendars in 1752. Other places converted earlier or later, so one much learn about dating in each country your research is being done. As adopted in England: "Eleven days were dropped out of the calendar in September, the day after Wednesday, 2 September, being called Thursday, 14 September. The year began with 1 January following 31 December 1751. The Dominical Letters for this year are three: since it was a Leap Year, the Letter for January and February was E, that from 1 March to 2 September was D, and that from 14 September to 31 December was A. Easter Day in 1752 was calculated according to Old Style; Easter Day for 1753 was calculated according to New Style." The alpha characters just described, as quoted from the source above has a series of charts based on these alpha characters as it pertains to when Easter falls in any particular year. I’ve not personally used these charts, so please don’t ask me to look anything up. <2. Regarding 'leap' years, how was that aspect handled in the old system? > According the the source, cited above, it has this to say and I will quote two paragraphs which I believe might answer the question about leap year. "Throughout the Middle Ages, and in some countries for much longer, the calendar in use was that known as the Julian, because it was originally introduced by Julius Caesar in 45 B.C. The way of reckoning is now known as the Old Style, in contradistinction to the New Style, that is to say reckoning by the Georgian calendar, introduced by Pope Gregory XIII in 1582. The Julian calendar set up a common year consisting of 365 days, while every fourth year was to contain an extra day, the sixth calends of March (24 February) being doubled and the year therefore being described as annus bissextilis. This latter device was intended to rectify, at regular intervals, the accumulated discrepancy between the calendar year of 365 days and the solar year, calculated by the astronomers at 365-1/4 days. The mistake was made however, of counting in the current year when deciding which was ‘every fourth year’, and in practice the bissextile years occurred in what we should call every third year. Thus an error rapidly accumulated, until the Emperor Augustus got rid of it by ordaining that twelve successive years should consist of 365 days only. The next bissextile or leap year was A.D. 4, and thereafter, as long as the Old Style lasted, every fourth year, in the modern sense, was a leap year." <3. I've seen many instances where someone was born, or had some other event identified using the old system, but passed away or had some other event documented which used the new or current system of dating - is there some method to determine the accuracy of the time or dating difference? > I would have to say, probably not. Other than it really looks strange in your own records when you see a date of death that occurs before the person was born, particularly babies whose deaths occurred really close to the time of birth and the change of calendar. A lot of computer programs, including PAF, pops up a potential error when you do this, but you need to ignore the error potential and put a notation in your notes part of the person’s record to indicate there is no error, that the dating is due to the calendar year change, usually recorded as being double dated. <4. Is there some method or practice commonly in existence which attempts to convert old system dates to the new system? I'd tend to think not, for there has to be a formula of some sort in place to help determine the difference? See question #3.> First and foremost, don’t attempt to convert old dates to new dates. Cite the dates as you find them in the record or source. I suggest, once again, that you note in your records that there was a change in calendar from March being the first month to January being the first month if you think someone might not know there was a calendar change. If you convert a date and fail to make a notation that you did the conversion, then you will either mess up another researcher or confuse them when they find a source that doesn’t agree with what you have. The only dates that should be converted to a "modern" date would be when the record cites a number for the month and only then do you go through the machinations of conversion only because our modern computers start a year with the month of January and not March. Start with March 26 as the first day of the first month April = 2 May = 3 June = 4 July = 5 August = 6 September = 7 October = 8 November = 9 December = 10 January = 11 February to March 25th = 12th month In your source, cite exactly what the record says - without converting anything. Anyone, with some intelligence, will realize that you have done the conversion by changing, say a 7th month to correlate be September by using 9. So someone born 7th 7mo 1645 would be born September 7th 1645. All you have done is convert the old numbers for the months to what it would be, even back then. The 7th month was September. Christie Trapp ________________________________________________________________________ AOL now offers free email to everyone. Find out more about what's free from AOL at AOL.com.