I once had somebody (an obnoxiously cheerful morning-person) ask me how I was just as I walked into the door at school. (this is 8am or so. I've been up for less than an hour)
My reply: "'Don't know yet."
Him: "Can't complain?
Me: "Not yet"
While I was kind of annoyed (and considered saying "Not until now") and also rather amused, it took me until now, when I was recounting the anecdote, to realize that there is an underlying principle demonstrated that it is important to remember:
Your day does not begin bad. It only becomes bad when you let it become bad.
The first bit is obvious but still important to remember; your day is innocent until proven guilty. The second part is harder to remind yourself of but is also very true: you are the jury of your own day (to continue the metaphor) and you can choose to determine it innocent. That being said, there are days that are bad and you have to accept that. Nonetheless, you have the power to choose how your day is.