Take my word for it, this sign is about a discounted movie screening that is taking place “between 1pm to 3pm”.
Using “to” with “between” sounds terrible, but I know why people write this way because I’ve done it. You start out thinking about two times in one sense, then your thinking unaccountably changes before you finish writing what you set out to write. Gah!
When stating a range of times, here are some acceptable formats to use:
We are open from 9 a.m. to 6 p.m. [from/to]
We are open 9 a.m. to 6 p.m. [to]
We are open 9 a.m. – 6 p.m. [en dash, not hyphen]
Drop off your donation between 9 a.m. and 6 p.m. [between/and]
In the case of a movie screening, I definitely wouldn’t use “between/and” because the movie isn’t happening at one point between the two times mentioned, it’s happening for the entire length of time. I probably wouldn’t even use from/to, though. I’d probably use “start at” and “finish at”.
The movie will start at 1 p.m. and finish at 2 p.m.