I'm enquiring as to the legality of parking along the street where a layby has been provided, but the parking restriction sign is ambiguous (to me anyway).

Mon-Sat
8am-9pm
30 mins
No return within 30 mins

Sorry, I can't seem to attach an image of the sign.

Does this mean parking is also permitted outside of these times, or parking is forbidden between late Saturday evening and Monday morning. In other words, would I be allowed to park there on Sunday evening?