Calendar Years
Accuracy Alert

How I made this calendar;

First a quick note;

There are currently only 14 yearly calendars in use today. These calendars have been in use for about, a little over 2000 years or so, give or take a few years. When Julius Caesar established them.

Each yearly calendar starts on January 1rst.

January 1rst can and does start on a Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, and,or Sunday. That is seven yearly calendars,, one for each day of the week, (for the regular years), and then there are another seven calendars for the leap years, making it a total of 14 yearly calendars in all.

All of the calendars are used in the rotation. What I mean by that is,, if you start with a calendar, lets just say January 1 is on a Monday and it is a regular year, then December 31 would also be on a Monday. Hence, the next calendar year would start on Tuesday, and so forth. The leap years add an extra day, so every four years the calendar would jump ahead an extra day, thus changing the rotation. All fourteen calendars are used in the rotation, which is how I made these calendars.

I started with the current year and then I put the calendars in rotation up to the year 2099.

Then I put the calendars in rotation backwards to the year 1583. Honestly, I don't know if the early Americans used the Julian Calendar or the Julian Calendar with the Gregorian Mathematical revision, at the time. (I will have to look that up a bit more.)

The year 1582 is when Pope Gregory added to the Julian calendar when he did his mathematical revision. The inspiration and,or necessity for Pope Gregory to do this was that he wanted to correct the proper date of the Easter holiday in accordance with the vernal equinox. (The vernal equinox is the spring equinox in the northern hemisphere and the fall equinox in the southern hemisphere.)

You can read more about this "here" on Wikipedia, or do your own internet search to find many other articles and resources to look it up.

(Quick Note; According to my research, Pope Gregory removed 10 days from the year 1582, however, according to my math, the calendar should have been off 12 days. I will be writing more about this eventually. When I get around to it.)

The mathematical difference between the Julian Calendar and the Gregorian Calendar revision is;

The Julian calendar was based on the calendar year being 365 days and 6 hours long. The actually measurement and,or the amount of time it takes the earth to make one full orbit around the sun is 365 Days, 5 hours, 48 minutes, and 46 or 48 seconds.

(Unfortunately I found two different numbers for the seconds while looking stuff up on the internet, and I don't know precisely which one is the accurate one yet.)

Either way, that is a difference of 11 minutes and 12 or 14 seconds per year.

After over 1500 years you can see how the Julian Calendar would have been off a few days or more.

Pope Gregory proposed his revision in the earlier part of 1582, and it was implemented in the later part of 1582, but only by the countries that accepted the revision at the time. Not all countries accepted the revision at first and it wasn't until the 1900's that all countries concurrently used the Julian calendar with the Gregorian mathematical revision.

(Another quick note; Pope Gregory also changed the date of the New Year, but that is another article I will have to get around to writing. You can look this stuff up on the internet for yourself if you want to know more about it for yourself, for right now.)

As per my calendar website, for the year 1582, I could not find any way to accurately figure out what the proper days of the week were for the dates of that year, so I just went with using the calendar rotation from the prior year(s).

As for the years prior to 1582,, at first, I didn't know how to figure out what the days of the week were for the dates of the year. Then I thought, I would look up some of the notable people who were born prior to 1582 to see if I could find a reference. I looked up a bunch of people but didn't really find a reference.

Then, about three weeks later, when I wasn't even looking for it,, I was looking up something else just for curiosity, I found Christopher Columbus's journal from 1492.

In Christopher Columbus's journal he makes references to the days of the week with the dates of the year.

I used this for the rotation of the calendars for all of the years prior to 1582,, all the way back to 45 BC.

I started with 1492, from Christopher Columbus's journal and I put the calendars in rotation from 1492 up to 1581. I also used it for 1582, but there is no way to tell how accurate the days of the week are for that year, because that is the year Pope Gregory removed 10 days from the calendar and changed it. I also used it for the rotation of the calendar back to the year 45 BC.

(Note; There was no zero year. The calendar went from 1 BC to 1 AD.)

As for the accuracy of my calendar website;

My calendar website is mostly, just for entertainment purposes,, to see what weekday a date of the year is on. It is accurate from the current year back to 1900 as I have compared it to other, actual calendars I have found on the internet and other places. That is; it is accurate for all of the countries that used the Julian calendar with the Gregorian revision at the time. It should also be accurate in the same respect back to the year 1583, although I could find no actual calendars prior to 1900 to compare it too.

The year 1582 is the year Pope Gregory made his revision of the Julian calendar. As far as I can tell, there is no way for me to accurately label the days of the week to the dates of that year, because that is the year the dates changed (for some countries).

For the years prior to 1582, the accuracy of the days of the week pertaining to the dates of the year are based on Christopher Columbus's journal from 1492.

One final, quick accuracy note for now;

According to my research, (just looking stuff up on the internet), the names of the days of the week, i.e., Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, and Sunday, came about sometime in the first couple of centuries AD.

Before this, they still had seven days a week, and the names of the days of the week were quite similar, but they were just different.