In what context can I place a preposition in front of “today”, "this Friday" etc.
I know these following sentences is wrong since there is no need to place a prep. before them
That will officially start on this Friday.
How are you feeling on today?
But can I use a prep. before them in other sentences, as follows
We will get this done by this Friday.
The launch of this rocket has been scheduled for tomorrow.
So, I want to know In what context I can place a preposition in front of “today”, "this Friday" etc.