Preposition ‘of’ usage

[nordway]

Hi, are these two cases of using the preposition ‘of’ too exotic or they are real? I found them in the Longman dictionary.
The first one.
22 American English spoken used in giving the time, to mean 'before' synonym 'to' British English
It's a quarter OF seven (=6.45). Instead of It’s a quarter TO seven.

The second one
25 of an evening/of a weekend etc British English in the evenings, at weekends etc:
We often used to walk by the river OF an evening.
Instead of
We often used to walk by the river in the evenings.

[SoothingDave]

"Quarter of seven" is real, though "quarter till/to seven" is more common.

[Rover_KE]

We often used to walk by the river OF an evening.

This is fine — at least in BE.

This (from Way Out West) always makes me laugh:

LAUREL: He's dead just at present.

HARDY: What did he die of?

LAUREL: I think he died of a Tuesday.

Rover