Thanks a lot, it's appreciated. The easiest way is to wait for an update of Pigeon Planner, which should hopefully not take too long.
The other way is to put the files into the correct place manually. I included all translation files in this post, they are the files ending in .mo.
First find the Pigeon Planner installation directory, on Windows this should be something like c:\Program Files (x86)\Pigeon Planner. Then:
1. In the languages directory, create a subdirectory called sq\LC_MESSAGES and place pigeonplanner.mo there.
2. In the share\locale directory, do the same. Create sq\LC_MESSAGES but this time place all the other files in there.
If it's not entirely clear, you should see all other languages there as well as an example.
Next time you restart Pigeon, Planner it should automatically detect these files. If not, the language can be changed in the preferences.