More About Dates

Many different calendar systems were used in the during the last four centuries—including the French Republican, Julian, Jewish or Hebrew, and the Gregorian calendar that most of us use today.  The Gregorian calendar came into existence on Thursday, 4 October 1582.  However, the various countries and states of the world switched to the Gregorian calendar at different times and at their own leisurely schedule.  To give you a few examples, the Gregorian calendar was invalid and not used in the following places prior to the dates given below:

Unfortunately, many genealogists wrongly believe that the whole world switched to the Gregorian calendar in 1752.  The above table illustrates the extent of their error.  The Russian Orthodox Church still uses the Julian calendar today.

As genealogists, it is important that we know the calendar applicable to the places and to each event that we record.  The table on page 103 of our Adventures in Genealogy book provides the real dates when 40 of the main countries and states of the world switched to the Gregorian calendar.  From 10 to 13 days were lost from the year during which each country switched.  To complicate matters, many countries—such as France—switched more than once.

The Offset and Short Years

March was the first month of the year according to the ancient Roman calendar.  Thus, based on their Latin numbers, the seventh month was named September, the eight month was named October, the ninth was named November, and the tenth month was December.  To adjust the length of the year every four years, an extra day was added to the last month of the year:  February.

A change occurred in 153 B.C. when the 1st of January became the date of entry into office for consuls and magistrates.  Thus, when Julius Caesar established the Julian calendar in 46 B.C., the official year began on 1 January and ended on 31 December.

During the middle ages, however, different countries adopted other dates for the beginning of the year.  The most common start dates were 25 December, 1 January, 1 March, and 25 March.

Most of the northern European countries, including England and Ireland, changed to 25 March (the Feast of the Annunciation day) as the start of their legal and ecclesiastical year.  This day, exactly nine months before Christmas, commemorates the date when the Virgin Mary was told that she would be the mother of the Messiah.  Thus, 24 March became the last day of the year.  This offset year calendar was used in various countries until the year shown below.

In France, New Year's Day was changed from 1 April to 1 January.  People who still celebrated New Year's Day on 1 April were known as April fools.

The important result of these changes was that the switch year lost three months.  For example, the year 1751 lacked a January, February, and the first 24 days of March in England, Ireland, the American colonies, English Canada, and the other English possessions.  A&D will stop you if you try to enter a date within this missing period.

Use of Numbers

Unfortunately, many of the dates on historic documents have the month recorded in numeric format.  The reason for writing the month as a number was typically a religious one: the names of eight of the 12 months came from Roman gods.  Religious people, such as the Puritans and Quakers, objected to commemorating pagan gods by writing their names.

This creates major problems for genealogists.  When a date is recorded in all numeric form, you must decide whether the date is in month-day-year or in day-month-year order.  Further, if an offset calendar applied to the event, a month value of "1" referred to March, a "2" meant April, "10" was December, and so on.

Should you convert dates?

As a general rule, you should not try to convert all dates to today's Gregorian calendar.  Too many well-meaning authors and genealogists try to help their readers by converting dates.  In fact, they only confuse the issue and potentially cause errors to be introduced into their family history.

The only safe way to avoid problems and assure accuracy is to identify and record the calendar applicable to any non-Gregorian date, if known.  In most cases, the calendar applicable to a particular date and place will be known with a very high degree of certainty.  A&D makes this very easy for you; it automatically identifies and records the calendar system (using a standard code such as "OS") in those cases where the non-Gregorian calendar is certain.  You can also manually enter the calendar codes.

For further detailed information on these date topics, see Chapter 14 of our Adventures in Genealogy book.  The 20 pages of that chapter also cover other date features of A&D—such as Double Dating, year ranges, the date that a living person was last known to be living, referencing notes or a source within a date field, LDS date entries, and the Eternal Calendar.

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