It is ironic that I come across your blog. I too have felt the hairs on the back of my neck stand when someone is speaking of a time frame and specifically tagging the "on", to it.
Unfortunately, it is now accepted as part of speech and even presented in public forum.
Imagine if you will, president of the University presenting graduate degrees and referring to a special program that is going to begin "on tomorrow." I knew then it was a losing battle.