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Date Calculator Index
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Date Calculator - Macintosh Software for Genealogists

Date Calculator Icon The Date Calculator is MacOS X application for many date and time calculations useful to genealogists. It is free if you are a registered user of GEDitCOM II. For others you can get it at the Mac App store or you can click Buy Now below to order here (note the App store version requires Mac with Intel chips, but the one here will work on both Intel and older G4 Macs).

The Date Calculator has the following capabilities and more:


UB IconClick the link in the following table to download the Date Calculator. The download is a 100% functional version, but will ask for an unlocking code every time it starts. You can eliminate the message by purchasing a license and entering the code you will get. If you are a registered user of GEDitCOM II you can enter your GEDitCOM II unlocking code to eliminate the message.

Date Calculator Download Date Size (MB)
Date Calculator, version 2.1
Requires MacOS 10.9 (Mavericks) or newer
12 JUN 2018 2.1
Date Calculator, version 2.0
Requires MacOS 10.4 (Tiger) through 10.8 (Mountain Lion)
7 JAN 2011 0.73


If you are not a registered user of GEDitCOM II, you can purchase a separate license for the Date Calculator here using most credit cards or your PayPal account. In you prefer, you can get the Date Calculator at the Mac App store (but that version requires Mac with Intel chips). To order here, click on the following "Buy Now" button and then:

  1. To pay by credit card, click the "Continue" link on the lower left of the invoice screen that appears.
  2. To pay using PayPal, use the log-in fields on the lower right.
Product Cost Buy
Date Calculator license
This license works for any version; get the version appropriate for your Mac from the above downloads table. Upgrading versions is free (use same license as before).

After completing your purchase, you will get a confirmation email from PayPal about the charge to your credit card or PayPal account. Your permanent code will arrive by email from (typically in 1-3 days). If you purchase and install from the Mac App store, it will be ready to run; you won't need to enter a code.

Additional Information

Date Calculator uses the date conversion utilities written by Scott E. Lee. He has written a Date Convertor Web Site that converts precise dates between Gregorian, Julian, and Hebrew calendars. He has also posted an excellent Calendar Overview about those calendars. Most of his overview is included (with permission) in the Date Calculator help.