Cfxtrjtrk

People will say: He usually comes round here about 8 o'clock of an evening, or 10 o'clock of a morning, or of a Saturday afternoon.

Is this standard English? I tend to associate it with Londoners.

ODO says that of an evening(or morning etc,) is an informal expression meaning:

• at some time in the evenings (or mornings etc.).

Examples:

• If you're generally stuck for something to have for dinner of an evening, then hop along to The Red Kitchen and see what people there are having.


• Besides, the three of you look impossibly cute when you're sat like that of an evening.
  


• Now - you MUST bring Connie over to the club for dinner of an evening soon; my wife was only talking to her last week and she was saying it's been so long since we've all eaten together!

Or

• on most evenings (or mornings etc.).

Examples:

• When I was growing up The Archers was a regular feature, always on in the kitchen of an evening and my sister and I were forced to keep quiet for the critical 15 minutes.


• Thanks for confirming my long-held belief that I'm better off slowly destroying my liver than staying in of an evening.
  


• We've come to delight in having a few tealights burning of an evening.
  

From: The American Heritage ® Dictionary of the English Language:

• “Some speakers of vernacular English varieties, particularly in isolated or mountainous regions of the southern United States, use phrases such as of a night or of an evening in place of Standard English at night or in the evening, as in We’d go hunting of an evening.”

(www.englishforums.com/English/CorrectGrammar)

The expression "of an evening" and the like would have been standard usage in Old English - by which I mean the language as it was in the Anglo-Saxon era. OE as you may know was a language which often used inflection of the noun without needing a preposition and in all of the MS I have seen the case form used for this expression is genitive - which in ME employs "of". So in OE one would use "æfenes" the genitive case form of "æfen"

I grew up and still live in the American South (NE Georgia). "Old people" I grew up around often used this expression.

"Many a time of an evening, when I sat alone looking at the fire, I thought, after all there was no fire like the forge fire and the kitchen fire at home." Great Expectations, by Charles Dickens, chapter 34 - "In this unreasonable restlessness and pain of mind I would roam the streets of an evening, wandering by those offices and houses where I had left the petitions." Great Expectations, chapter 56. "When she came there of an evening, she always shrunk from accepting his escort home, and ran away with me instead." David Copperfield, by Charles Dickens, chapter 16.