Assuming banks, and other business or subsystems, are open by default is a bit silly when you have to interact with more than a handful.
Why not just assume they are not available on any given day unless proven otherwise?
A positive list of what's actually confirmed is much better than trying to find every obscure holiday everywhere on Earth and then adding it to a negative list.
Why not just assume they are not available on any given day unless proven otherwise?
A positive list of what's actually confirmed is much better than trying to find every obscure holiday everywhere on Earth and then adding it to a negative list.