Look at the Edinburgh Trad Music and Session Hub on FB - their Featured tab has a Google Doc spreadsheet (don't post there until you've found and it) and the Gig Guide monthly newsletter complements that for other types of gig. Finding out what's on in Glasgow is a lot more difficult but there is a lot on there too.

Dunno about Inverness. Dunfermline FC meets on Wednesdays and things happen in Falkirk, Stirling and Aberdeen.