Say, thunderbird is installed in one of your computers. So, the question is, how can you sync lightning to another pc? Here is the answer...

-in the lightning that is readily available: -open thunderbird menu=>From the events and tasks menu, export the calendar as ics file to dropbox -*open thunderbird menu=>New message=>Calendar=>On the network=>select ics=> enter the location in file:///c:/folder1/folder2/Home.ics format

-in the pc that you want to transfer lightning -install lightning add-on -delete home calendar -do the step in * for this lightning as well

Having done these steps once, the changes in your calendar will be automatically synced to each computer.

My approach is to use an online Calendar and synch Lighting to it. It's automatic and once set up, needs no further intervention from you. Exporting and importing means you have to choose to then carry out a series of specific actions. On each and every one of your computers.

I have tried your approach with Google Calendar, and it screwed up after a while. I believe that Dropbox is the most reliable syncing service on the internet and it is good practice to use it for Lightning as well.

It's fine if you can isolate the particular files you want to work with. But various files in the Thunderbird profile are hard coded and don't play nicely, for example the address book and calendar data files. You might be able to fool it with symlinks and the like.

Some users try to bypass this by putting the entire profile onto Dropbox. There are several problems with this. It's stupidly inefficient to copy your entire mail store up and down. Sharing a profile leads to a possibility of concurrent access from multiple devices, which it isn't designed for. Some add-ons are sensitive to the OS and to the version level of both Thunderbird and the add-on itself, so you have the additional challenge of keeping all installations compatible. And some add-ons are simply not available on all the platforms, or require platform-specific builds. As a user of Linux and Windows, several of these concerns are show-shoppers for me.

I simply wouldn't have the patience for the endless cycle of exporting, importing and copying you have committed to. Whereas caldav "just works" for me.

I'm glad you have found a solution that works for you. I felt I should point out some of the pitfalls for anyone considering doing the same.

I didn't experience any of the pitfalls that you are mentioning. Any changes you make to the calendars will be synced automatically after the initial tedious configuration. So, I can say that my approach is working smoothly and reliably. Anyways, you have shared some technical details about my approach and I greatly appreciate it