Proper English - on tomorrow?

Lately I notice many people saying, "on tomorrow," or something similar.  Why?  Hello, proper English?

An example would be, "I am going to do that on today."   What the H-E-double hockey sticks!? Does that sound right to you?  Is that the English language we learned? Why would someone not just say, "I am going to do that today"?

Now, if for example, you were going to specify a later day in the week, I could understand, "I am going to work out on Wednesday."  "I am going to rehearse on the 23rd."  Those sound better.   The "on" though not always necessary in those situations, but still fits.

So if you catch someone saying "..on today," or "..on tomorrow" shake your head at them in disgust for me.  Thanks.