Linux dont use .exe-files at all, so you must download Rainlendar-file for Linux-distribution.
www.rainlendar.net/cms/index.php?option=com_rny_download&Itemid=32
Debian/Ubuntu-version works also in Mint.
Use Gdebi-installer. If you dont have Gdebi, you can install it in terminal; sudo apt-get install gdebi
Right click on file, and gdebi install Rainlendar.
Make automatic startup on desktop for Rainlendar in startup menu of your distribution:
File system > usr > bin > Rainlendar2.
This works for Ubuntu, Xubuntu and Mint. In Xubuntu I have small error:
www.rainlendar.net/cms/index.php?option=com_kunena&Itemid=42&func=view&catid=3&id=18342#18342
Others dont know.