Remove a holiday

I have this exact problem and I don't understand what to do. How can I stop iDoceo from treating St Patrick's Day as a public holiday? It is a normal school day.

iDoceo does not treat any day as holiday unless you configure it as such.
You've configured St Patrick's day as a holiday in your calendar and if you'd like to remove it, it has to be done from the very same view.
Main screen > Three dots button (top central bar) > Calendar > Holidays