It's very interesting that this thread has continued over such a long period of time. The use of "on" before tomorrow or yesterday irritates me to no end. As a 41 year old Black person with family of southern descent (not decent), I can say that this is not a term taught to or used mostly by this group. I had never heard the term until recent years, and it certainly is not used in my family by dentists, lawyers, judges, teachers, office workers, secretaries, or anyone else.

As an employee of a federal agency, I work with people from all over the country. Most recently, I have heard this term used by a white woman from Michigan. She always says things like, "I will check in with you on tomorrow and see where we are." My grandmother, who was raised in the Chicago suburbs by her southern parents, had never heard the phrase until recently. She says the secretary (white) at her doctor's office uses it. I have begun to hear the term more and more (from people of various races). I assumed it was a regional dialect. It's annoying to me no matter who says it or where they are from...But I am also annoyed by "ax" or "ass" rather than "asK", "yous" rather than "you", and the use of prepositions at the end of a sentence.