And here is a shot of the flowers....

vince

What size are the leaves and flowers? ????Syringa meyeri???? if they are a good bit smaller than on regular lilacs.

what about Bloomerang...since it is blooming in August...but leaves do not look the same.

Or Syringa x 'Josee'.

Here is a link that might be useful: Josee Reblooming Lilac

Thanks for the comments!

The leaves are much more rounded than the "typical" lilacs, and on the bush they are rather small, about 1 to 1.5 inches in diameter. I've never seen one of these at the big box stores. It came from a nice house in an affluent area.

Meyeri and Josee both look like good possibilities from what I see of the leaf images. That it was still in bloom in August might be the decision maker.....

vince