Hello @RAG
I am not sure if you are aware of the sidebar slider by @hoopyfrood, a part of the TW-EventCal which incorporates two buttons for Left and Right Sidebars.
Look at this non-JS Calendar discussion
It shows the required tiddlers that you need to add to your wiki if you want only want the sidebar change functionality.
Update
The config tiddler $:/plugins/SB-slider/config shows what tiddlers are required.
See this link TW-EventCal — Calendar displaying tagged events