Time - "the back of xx o clock"

[Hungrycaterpillarsmummy]

This is just my thoughts spilling out but my husband just said to me "I've told your dad I'll be round at the back of 11" and i'm like so is that 5 past 11 or 5 to 12? And he laughed because he has definitely explained it to me before and I just can't wrap my head around it.
The back of something, to me, sounds like it would be the end. So I imagine it to be closer to 12.
I know I am wrong. But the saying is bullshit.
There. I said it.

Never heard 'back of 11' or 'outwith'.

Londoner.

Yes there is agreement. Everyone has said it's after 11, up until 11:30, but never later.

The 'back' of the hour is until 11:30.

I think it depends on where you see yourself in the analogy. If you see yourself facing 11:00, then the back of you would be towards 12:00, so you'd expect them near 12:00.

but if you saw yourself facing 12:00, then the back of you would be 11:00, so you'd expect them nearer 11:00.

It is a word?

I agree with the PP who think it is before 11. It sounds as if it is sneaking up on 11 from behind.

So about 10.45/10.50.

Are you Scottish?

My husband uses the phrase too and I’ve always assumed he means at the end of the hour but also knew that wasn’t right.

Thanks to those who explained! Now I know!

Also Scottish, also this.