DateTree for Mac OS X is available by following the link below. This version works under Mac OS X 10.8 and above, including Catalina (64 bit).

DateTree 1.3 0.7Mb - click here

Once you've clicked on the above link, the DateTree software will be downloaded onto your computer. It is distributed in .zip format. (Your browser may automatically open this file for you, or you may need to double click on it.) A Finder window will open with the DateTree application inside it, and you can drag the application right out of the Finder window and into your applications folder to install it. The first time you run it, right click on the application then click the "Open" menu item and button.

If you need to install DateTree on Mac OS X 10.6 or 10.7, then download version 1.2 instead.

If you need to install DateTree on a G3 or G4 processor, or Mac OS X versions before 10.6, then download version 1.1 instead.