When booking a vacation in another country, be aware of that country’s holidays. Not only can airfares be higher during a country’s holiday, but stores, museums, restaurants, etc. may be closed for a day or more than you might have planned. Train schedules usually run on a reduced schedule on holidays as well.
I remember a time years ago when my parents were in Mexico but their travelers checks were still home in Chicago (I’m sure my dad didn’t let my mom forget about this mistake for years!). They happened to arrive in Mexico on a weekend when there was a Monday holiday, so it was awhile before the banks were open for them to get the funds they needed. It’s easier now with ATM machines all over, but everything else is still affected by holidays.