I have taught at a public, inner city school in south Florida, and a rural school in South Carolina, and had never heard the phrase "on tomorrow" or "on yesterday" until I started teaching in Mobile, Alabama. I hear it just about every single day during the announcements from the principal. Every time she says it, I cringe! I simply thought she had horrible grammar! Tonight I was watching Saturday Night Live in which they did a hilarious skit at Booker T Washington high school prom. The principal used the term 2-3 times. I busted out laughing, then started googling the expression and found this site. I definitely think it is a southern thing, and it is regional to New Orleans, Mobile, and southern Georgia areas after reading the posts here.