A Change In Time

If you've done much genealogical research, you may have noticed the practice of "double Dating." In many early colonial American records, you will find entries like "12 February 1732/33," or "14 January 1701/02." The explanation for this seemingly strange practice is found in the history books.

The various calendars in use prior to 46 B.C. were very inaccurate. It was in this year that Julius Caesar instituted a new (the Julian) calendar, which brought together lunar and solar time. Caesar determined that the solar year was 365 days and 6 hours, so his calendar made provisions for an extra day to be added every four years. But His calculations were off by 11 minutes and 14 seconds. Consequently, over the centuries, solar and lunar time began to drift apart again.

By the year 1582, the deviation amounted to ten days. It was in this year that Pope Gregory XIII reformed the calendar. He eliminated the ten-day discrepancy by directing that 4 October 1582 be followed by 15 October. Since the Julian error of 11 minutes and 14 seconds amounted to three days every 400 years, he directed that those three days be dropped from the calendar by not observing any year which ended with two zeros as a leap year, unless the first two digits were divisible by four. Therefore, the years 1700, 1800 and 1900 were not leap years. But the year 1600 was, as will be the year 2000. By these simple expedients, Gregory once again brought lunar and solar time together.

Not all countries, however, accepted the Gregorian calendar at the same time. England and her colonies, in fact, waited until 1752 before embracing the new calendar. By that time, of course, the difference was eleven days. The eleven days were duly dropped from the calendar by the direction of Parliament that the day following 2 September 1752 would be 14 September.

Many people at the time added eleven days to their birthdates so they might celebrate the exact anniversary. This explains why original records indicate that George Washington was born on 11 February, but that after 1752, his birthdate has always been considered to be 22 February. At this point, we must regretfully throw one last fly into the ointment. The original records indicate that George Washington was born on 11 February 1731. We recognize Washington's birthdate as 22 February 1732.

Now, we have already accounted for the eleven-day discrepancy. What about this business of an extra year?

For a long time, England and her colonies had observed two separate New Year's Days. The government and civil authorities considered 25 March to be New Year's Day and the people at large considered 1 January to be the beginning of the new year.

Needless to say, there was quite a bit of confusion. In an attempt to clarify things, many people took to using both years in their notations. For example, you will find dates similar to Washington's birthday written 1731/32. Or, you may find the same information expressed as 1731 O.S. (old Style), or 1732 N.S. (new style). At any rate, along with reconciling solar and lunar time in 1752, the English government also officially recognized 1 January as New Year's Day.

You should only encounter double dating of years in or prior to 1752. For the reasons given above, you will only encounter double dating of date (e.g. 1/12 February 3/14 March) in the months January, February and March in or prior to 1752.

­from How To Trace Your Family Tree by the American Genealogical Research Institute Staff