The cheapest version of travel planning does not worry about all local events; it is a superfluous expenditure of energy for many.
The minimum viable is to check public holidays and strikes, not the entire cultural calendar, unless it is the main goal.
If you go to Amsterdam for a trade show, King's Day only matters if it blocks your access to the hotel or airport, otherwise, it's noise.
Focus on the objective and cost; the rest is often secondary.