Delmarva Settlers

Calendar and dating conventions
Calendar information and dating conventions in the 17th and early 18th centuries.

The Julian Calendar
The Gregorian Calendar
Date Conventions in Early Colonial America
Regnal Years
Movable and Immovable Days

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The Julian Calendar

The Julian calendar was introduced by the Roman Emperor, Julius Caesar, in 45 BC. The previous Roman calendar was complicated in structure and subject to arbitrary alterations, allowing influential pontiffs to exploit the collective reckoning of the civil year for personal or political ends. Intending to curb corruption and prevent disorder, Julius Caesar reorganized the calendar to bring the civil year into alignment with the movements of the sun.


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"...He corrected the calendar, which had for some time become extremely confused, through the unwarrantable liberty which the pontiffs had taken in the article of intercalation. To such a height had this abuse proceeded, that neither the festivals designed for the harvest fell in summer, nor those for the vintage in autumn. He accommodated the year to the course of the sun, ordaining that in future it should consist of three hundred and sixty-five days without any intercalary month; and that every fourth year an intercalary day should be inserted."

Suetonius Tranquillus - The Lives of the Twelve Caesars, Vol 1: Julius Caesar, XL.

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While being more efficient than the previous structure, the Julian calendar produced an error that resulted in a one-day discrepancy in the tropical year every 128 years. Additionally, calculating the yearly date for Easter was difficult and often inaccurate under the Julian calendar. A solution to this problem was offered in 1582 with the Gregorian calendar.

The Gregorian Calendar

The Gregorian calendar was proposed by Aloysius Lilius, a physician from Naples in Italy. It was designed to correct the errors in the Julian calendar by extending the length of the tropical year, increasing the span between calendric discrepancies from 128 years to 3,300 years. The new calendar was adopted by Pope Gregory XIII, in accordance with instructions from the Council of Trent, and was decreed in a papal bull in February of 1582.

"...We thus remove and absolutely abolish the old calendar and we want that all the patriarchs, primacies, archbishops, bishops, abbots and other leaders of Churches put into force for the reading of the divine office and the celebration of the festivals, each one in his Church, monastery, convent, command, army or diocese, the new calendar, to which was adapted the martyrology, and make use only of this one, as well as all the other priests and clerks, secular and regular, of the both genders, as well as soldiers and all Christians, this calendar whose use will start after the ten days removal of October 1582."

Pope Gregory XIII - Inter Gravissimas, XIV; 1582.

While most nations changed to the Gregorian calendar in 1582, England-- alone among major European nations-- clung to the old Julian calendar until 1752. As such, most early records from early colonial North America reflect the dating conventions of the Julian calendar.

Date Conventions in Early Colonial America
Information to assist in interpreting probate inventories, wills, land grants, and judicial records.

Dating conventions used in 17th- and early 18th-century documentary records can be confusing to the modern researcher, as most colonial record keepers reckoned the year according to the standards of the Julian calendar. Here follows a brief list of common standards from the Julian calendar to assist researchers, students, and family historians in understanding the dating conventions found in early probate inventories, wills, land grants, and judicial records:

* Dates preceding England's change from the Julian to the Gregorian calendar in 1752 are known as O.S.(Old Style or Julian). Dates since 1752 are known as N.S. (New Style).

* By act of Parliament in 1752, England began to use the New Style calendar, and the day after September 2 of that year became September 14 in England and all her colonies.

* Most dates in historical scholarship have been converted to the Gregorian or New Style date.

* March 25th was the first day of the new year in the Julian calendar. March 24th was the last day of the previous year. March was the first month of the year, April, the second, and so on, with February as the twelfth and last month of the year.

* Since the first day of the year was March 25 prior to 1752, Great Britain and the British colonies celebrated New Year's Day on that date, a fact that is often reflected in church records. March 25 was also sometimes known as Lady's Day, Annunciation day, or Annunciation of the Virgin Mary.

* Because the new year started on March 25th, dates in early March were regarded as being part of one year, while dates in early April were considered to be part of another year. For example, March 3, 1656 and April 3, 1657 were separated by only 30 days.

* Records from January and February followed those from November and December, being later in the year, according to the Julian calendar.

* Colonial clerks also frequently abbreviated months by using a combination of a number and a "-ber ending. For example, 7ber (September), 8ber (October), 9ber (November), etc.

* Colonial clerks often recorded the month by its number, instead of its name. For example, "4th month, 1646," which would be June of 1646.

* Frequently, religious prejudices, as in the case of the Quakers in Pennsylvania, led many colonists to number the month rather than be forced to write the given name of it. In accordance with the Julian Calendar, January was the eleventh month and February the 12th month. Documents were dated as 15.12.85/86 or 15.1.85/86 (February 15, 1686).

*Prior to 1752, double dating was used in Great Britain and British North America for dates occurring between January 1st and March 24th (between the years 1582-1752), with clerks using a slash to indicate a recognition of the disparity between calendric systems. This is frequently seen in early records and is typically expressed as 1662/3, 1678/9, 1691/2, etc. When transcribing documents, it is important to record dates as they are shown in the original record.

To make matters even more confusing, the colonial Chesapeake region had a diverse and multi-national population during the 17th and 18th centuries, with many individuals originating from different areas of Europe. These settlers often followed the dating conventions of their homelands, in spite of English law or local custom. For instance, Scotland counted January 1st as the first of the year after 1600, and many Scottish settlers who served the community in the role of clerks used that standard in their record keeping.


Regnal Years
Reigns of 17th-century English Rulers.







The Interregnum


Charles II


James II


William and Mary




George I


George II



Movable and Immovable Days
Movable and Immovable Days in the ecclesiastical calendar.

Movable Days
Ash Wednesday, forty-six days before Easter
Whitsunday or Pentecost, seven weeks after Easter
Trinity Sunday, eight weeks after Easter

Immovable Days

January 1


January 13

St. Hilary

January 25

Conversion of St. Paul

February 2

Purification of the Virgin or Candlemas Day

February 24

St. Mathias the Apostle

March 25

Annunciation of the Virgin or Lady Day

April 23

St. George

April 25

St. Mark the Evangelist

June 24

Nativity of St. John the Baptist or Mid-Summer Day

June 29

Saints Peter and Paul

July 2

Visitation of the Virgin

July 15

St. Swithin

July 25

St. Christopher or Lammastide

August 15*

Assumption of the Virgin

September 29*

St. Michael the Archangel or Michaelmas

November 1

All Saints Day

November 11

St. Martin or Martinmas

November 30

St. Andrew

December 25


* Of these Immovable Days, the two that are mentioned most frequently in the Eastern Shore of Maryland's early records are August 15 and September 29.

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This project is in support of the Edward H. Nabb Research Center for Delmarva History and Culture
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