How long do birth control pills last in your system before you take another pill on a new day?

Pharmacology of BC: Tri-Sprintec contains norgestimate and ethinyl estradiol. These compounds have their own half-lives of elimination. After you take this pill, the peak concentrations are seen around 2 hours, however, there are also active metabolites that last in your system that have half lives varying from 17-36 hours. Small amounts then persist for 4-5 times the half life. http://tinyurl.com/hhtfs9z