Rated 5 out of 5 stars
Nice. Like it. And works as well in SeaMonkey 2.26.1. How about adding SeaMonkey into install.rdf?
 OK. Found the GitHub repository and forum. MaxVersion changed from 2.4.* to 2.26.*. Will try to keep up with further SeaMonkey versions, test the plugin and update accordingly. [/edit].
[edit 2] With current SM 2.32 and Ltg 3.7 (and the former SM 2.31 / Ltg 3.6b3) Year View is not working any longer... :-(. Version 4.4 didn't change anything. Issue posted in the GitHub forum. [/edit]