British English often comes with subtext and inferred meanings whereas American English tends to be more direct. Here's a video by an American who's been living in the UK for a while. In it, she describes some of the phrases that initially confused her.
I'd say midweek would be best as it's a bit quieter. I'm between five and eight hours ahead of most of the people on here, so I'll leave it up to someone else to recommend at time.
I hope this update doesn't mess up internal links and embedded videos like when you shifted from vBulletin.
I've just checked out their website - luraycaverns.com - and they're very impressive. One thing that confused me - if they were discovered in 1878, why does the tour guide wear an 18th century costume (I'm quoting the video)? That would date from at least 79 years before the caves were discovered!