When do you start issuing notices regarding late rent?

[Jennifer A.]

I just want to get a general feel for when everyone is issuing their late rent notices.  My rent is due on the 1st.  If not paid on the 1st, there is a $50 late fee.  After the 10th, there is an additional $3 per day for being late (added because I had a lovely tenant who had no motivation to pay earlier rather than later once they'd already incurred the $50 fee). 

Do you give your tenants until the 5th in case it is in the mail (although I would still impose the late fee)?  Or do you issue it immediately on the 2nd?

Thanks for the input.