# Calendar geek needed: Julian vs. Gregorian days of the week

+7 votes
253 views

I am trying to decide if Desire Toogood's recorded birth date 26 March 1734 could be wrong. The record also states it was the 2nd day of the week, so it should have been a Monday. And it was recorded in Massachusetts, so was under English calendar conventions.

The English switch to the Gregorian Calendar lopped off 11 days in September of 1752, with 2 September being followed by 14 September. My presumption is that if 14 September was a Thursday under the Gregorian calendar, then the previous day was still what we would call a Wednesday (i.e., 4th day of the week), but written under the official Julian calendar it was 2 September. That would mean that if this calculator had kept going, the 14th of September would instead have been a Monday. So looking at a date number that would have been a Monday under the Julian calendar, if you look at the same date number on the Gregorian calendar it was a Thursday.

But now I am getting confused because when I look around at some online date calculators, I don't see them behaving like I'd expect. For instance, this one does not seem to have a break in the calendar on 25 March for year numbers before 1752, i.e., 1734. It shows 25 March 1734 as a Monday, while 24 March 1734 is a Sunday, even those these dates were separated by 364 days and should have fallen on the same day of the week. The calculator insted seems to be thinking that under the Julian calendar, 25 March 1734 occured the day after 24 March 1734.

This one shows similar behavior: it reports 25 March 1734 as a Thursday under Gregorian and Monday under Julian, but then moving to 24 March 1734, it reports these were a Wednesday and a Sunday.

I feel like I have a fundamental misunderstanding about how the calendar change was implemented. Any clarity would be very much appreciated.

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edited

## 2 Answers

+6 votes
Not a geek by any means and I'm not intending to calculate it but books of common prayer (the old version of the prayer book)  used to have tables to calculate the date of Easter Sunday in any year. I

There are several online calculators that use these tables to calculate Easter Sunday. For 1734 they seem to agree that it was 25th April (Gregorian) 14th April Julian. Count back from that and you arrive at Monday 25th March.

I would call Monday the first day of the week so Tuesday would be  the 2nd. Googling found that  modern N  American calendars differ from European ones and have Sunday as the first day of the week. I have no idea which was used in 18th century America.

edited typo in date
by Helen Ford G2G6 Pilot (489k points)
edited
Looking at  the calculators you used they seem to be calculating correctly and then subtracting r the 11 days but are using a modern convention for a Jan 1 change of year.

The day before  Monday 25th March 1734, would have be,Sunday  24th March 1733. (though a few contemporary church registers by then use double dating for the first three months and in Scotland they already changed on 1 Jan)

Its a bit like the UK tax year, where for tax we still use the old pattern. The present tax year started on 6th April 2020 ( 11 days from March 25), it will end, 12 months later,  on 5 April.
+6 votes

The source of confusion here is not just the shift from the Julian to Gregorian calendar but the fact that the new year began on Lady Day (25th March). So 25 March 1734 was the day after the 24th March 1733 and the 24 March 1734 was indeed 364 days later. I doubt online calculators are going to handle this correctly.

I can confirm that Easter in 1734 was Sunday 14th April (in the Julian world) and therefore 25th March was indeed a Monday and the first day of the new year. I'm not sure you can assume that Sunday was universally considered the first day of the week. Even if it was, could the record have said second day of the year instead? That would seem more notable.

Cheney, C R, and Michael Jones. A Handbook of Dates: For Students of British History. Cambridge: Cambridge Univ. Press, 2004

by Matthew Fletcher G2G6 Pilot (138k points)
I've checked some other births from the same record on the americanancestors.org site (link in the profile)

Some are consistent with Sunday being the first day of the week but worryingly we have "Daniel Brown the son of Esek Brown Juner [sic] and Patience his wife was born November the 25: 1743 on the first day of the week". Unfortunately, November 25th 1743 was a Friday so now I doubt the accuracy of the transcriptions. If possible I would check an image of the actual record before drawing conclusions.

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