Honestly, I would just skip it and resume your normal dosing schedule in the am. You are on a every 12 hour schedule, and it would be one thing if it were just off by a little, but you are off by 6, 7 hours.. Not that it would harm you in any way, but you may end up with a few unpleasant side effects, especially since you're dosing twice daily.
If you find yourself frequently forgetting to take a dose...then find a way to remind yourself. Put the Rx bottle by your coffee pot (or OJ glass, etc)...or most cell phones now have the alarm feature that you could set a daily alarm to go off at your dose time, or even a bit before.
typically, this would be a question for your doctor or a pharmacist. walgreens almost always are open 24 hours a day and can answer questions like yours. as trival as it may seem to skip a dose...you still have to understand that the vast majority of people in this forum aren't qualified in any way to answer that question.