A place to exchange money on a Sunday?

So I am fresh off the plane in Taipei and I foolishly forgot to exchange money at the airport. Tomorrow is Sunday.
Can I exchange money somewhere (like a bank) for a decent rate, or will everything be closed?
I can wait until Monday if really necessary (I have an emergency amount) but I would prefer to exchange it tomorrow if possible.
Please advise.

Any ATM machine will work if you have a Visa, Mastercard, etc. logo on your ATM card. Fees will depend on your bank, but usually not a lot.

Just be aware that you might have a different PIN for use in foreign countries - I’m sure you’ll remember if you do. In any case, try the usual one first. Cathay bank machines are more reliable, I’ve found. Big hotels often have an exchange desk, too. If you’re not staying at a big hotel, just walk in and look as if you do.

Did you get your money… Most major department stores offer exchange at the courtesy desk. Let us know what you did for future reference.

I am hosting some couchsurfers right now and they are wondering where you could change money on a Sunday in Kaohsiung. I have no idea and a quick googling proved unhelpful so I figured I’ld ask here. Thanks for your help.

I forgot about this thread!
Update: I informally exchanged a small amount of money with a local friend. This was enough for one day, although it delayed several things (getting a cell phone for example). Then on Monday I exchanged the rest of the money at the bank.
I have heard that an ATM would work too.