Assegnate 5 su 5 stelle

This add-on works in Thunderbird 52.9.1 (64 bit) under Ubuntu 18.04 without issues for the part saving calendar data.
You can select the folder in which your calendar events (of lightning add on) have to be exported and the laps of time between every backup. You can select a script to execute when saving but it seems not to run. I select my own script in order to send my calendar data to Telegram using the small program telegram-send (https://pypi.org/project/telegram-send/). This option could be even integrated in the add-on as feature or it would be possible an integration with another cool program named Task coach
Another only problem of this add-on is that you can't manually backup your calendar data because there is simply no button for doing this.