Since when do we assume everyone uses the same calendar?
(I'd also avoid terminology like bi-monthly and semi-monthly as it's a predictable point of confusion.)
We are confused when TSA staff in the US talk about quart bags.
A quart is the easy one. It’s just a slightly smaller version of a liter. And it’s not like the UK doesn’t use pints which are just half of a slightly larger quart.
I’m sure there’s lots of language including unrelated to measurement which differs across the Anglosphere.
To me the main advantage of 24h time is that it is easier to mentally calculate time, so for example 3 hours after 11:00 is just 11+3, which is 14:00h.
So, we usually say, 8 o clock in third pair means PM, or 8 o clock in 1st pair means AM.