USPTO's by date is inclusive or exclusive?

[newpatenter]

If I have the following words from USPTO:

The patent issuance deadline is:
02/06/2019
Failure to perform patent issuance by the deadline will result in forfeiture of your approved patent application.

I have to act before the end of today, 02/05/2019, or I can wait and do it before the end of tomorrow?

[Brad]

Sorry I have no idea what form you are asking about as I have never seen that specific language before?   Patents are always issued on Tuesdays so are you certain this form came from the patent office and is not spam or someone trying to get money out of you?

I would call the USPTO help center and they can look up your application number and tell you how to proceed. 
Toll-Free: 888-786-0101

Also note that if the deadline says February 6 you should have until 11:59pm EST on February 6 (tomorrow) to file your reply.   Most deadlines at the patent office are extendable.