This plasmoid is a mix of two other applets.
The first one is a plasmoid named jmeniny and can be found to the following address:
The second one is a karamba (kde 3.5.x) file named eortologio and can be found to the following address:
With the command plasmapkg from konsole:
plasmapkg -i greek-eortologio-plasmoid-kde4-0.2.plasmoid
GUI installation doesn't work for me.