I suspect that Imperial starports are run without reference to local holidays. Or Imperial holidays for that matter. That's just an opinion, though. But I don't see anything for the Bad Guys to do and the PCs to undo in that scenario.Let's not forget local holidays...
"Oh, didn't you know all government offices are closed on St. Cyril's Day?"
"I am so sorry, I forgot to inform you last time we spoke about the Judge's vacation plans. He always takes the family skiing in the southern hemisphere over the long St. Cyril's Day weekend."
"How did you get that body off your ship when the SPA stevadores are off for St. Cryil's Day? You didn't unload it yourself did you?!!! Now the dock workers are going to picket your ship; you may never get off this planet!"
Hans