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Quick Lookup - FAQS

This site has been up since December 1995. I have been getting various e-mail since then, all very complimentary. And I appreciate it. There have been times when people have pointed out errors, minor corrections, and occasionaly requests for more or additional material. There have also been questions, some of which come up very often. I do respond to all e-mails, and answer any question that comes up and will continue to do so. Hopefully this page will be helpful.

NumberQuestion then Answer
1 Q:

Why is the year 2000 a leap year? I thought the Gregorian Calendar said the Centuries would not be leap years?


The Gregorian Calendar system, adopted in 1582, did indeed change the way leap year was calculated. the calculation comes in three (3) parts:

  1. The year is a Leap Year if the year is divisible by 4
  2. The year is divisible by 100 then it is not a Leap Year (the century rule)
  3. the year is divisible by 400 then it is a Leap Year

Consequently, the years 1700, 1800, 1900, 2100, 2200, 2300, 2500, 2600, 2700, 2900, 3000 (etc.) will NOT be Leap Years, but the years 1600, 2000, 2400, 2800 (etc.) will be Leap Years.

2 Q: Will I add the Year Correlation tables (those tables to tell you which calendar to use for any specified year) for the year XXXX?

For years after 1600 I do plan to put those correlation tables up as I get to them. If I actually get a request for a specific century (or a year in a specific century) I am much more inclined to get it done sooner rather than later.

However, for year prior to 1601 I have yet to figure out a way to show the transition from the Julian Calendar to the Gregorian Calendar in a way I like. Consequently this will wait a while. I will put the 17th and 18th Centuries (1601 - 1800) before I tackle this problem anyway.

3 Q: Do I mind if people add links pointing to my site, or a specific page within my site?

No, not at all. In fact I would encourage people to make the links (or at least create bookmarks) to my site. the site is placed up for reference for anyone in the world to access. I don't charge for access (as you already know) nor do I offer to pay anyone to place a link to my site.

I currently do not offer to sell anything to anyone. And I do all this work on my own time, because I enjoy it. My only reward is the e-mail I get. therefore, if I take long periods of non-update (I could go several months between updates) don't complain.

My only request is if you do place a link on your web page pointing to my site, you send me an e-mail with the URL of the page. I would like to add a link pointing back to it on my Pointers Here page. (Yes, I know I badly need to update that page.)

4 Q: Will I ever charge for access to my site?

No, not at all. I might eventually get around to preparing a package of Virtual Perpetual Calendars as hardcopy for sale. But for accessing this site via the World Wide Web, there is no charge now or in the forseeable future.

5 Q: Do you have a formula, algorithm or function that you can tell me to calculate the calendar?

The single word answer is: NO. the Virtual Perpetual Calendar site is comprised entirely of static web pages. there is no CGI routine that generates them.

As for a formula to calculate which calendar to use for which year, there probably is one. I have not devised it though. I have an Excel Spreadsheet that works out the correlation tables for me. If you wish to devise such a formula, feel free. However, remember that the Gregorian Calendar system was installed in 1582. Prior to 1582 the Julian Calendar was used, which has the primary difference in leap year calculation. Also note that different countries changed from the Julian Calendar to the Gregorian Calendar in different years. And all of the "transistion" years lost a number of days that varies depending on when the transistion occurred, and the laws in place to govern the transistion. It is a very difficult thing to properly represent.

6 Q: Can you tell me the date for Easter in the year XXXX?

This is not an easy question to answer. I have found a site that does a very good job of providing that answer: Calculation of the Ecclesiastical Calendar. Take a look there.

7 Q: Do you have a way to printout all the calendars and the correlation on a single page?
A: The original concept of the site started from just sort of page that appeared in telephone books when I was growing up. When I first created the site I considered trying to replicate that exactly using a word processor but realized that current laser printers at 300 DPI would not be able to print finely enough to make the text legible and still hold all 14 calendars on a single one sided page. Due to my current focus on other life issues I have not gotten back to this issue. My best suggestion is to print out 15 pages... one for each calendar and one for the correlation table make them double sided, and something like 4 reduced pages to one side. That should reduce the page count to 4 double sided pages. Get them laminated (both sides).

19th Century

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Leap Years

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