Clonazepam, or alternatively called Benzodiazepine, can stay in your urine for a period of up to 6 weeks. It stays in the blood for up to 48 hours. For a comprehensive list of the common drugs and how long they stay in your system go to this site: http://www.passyourdrugtest.com/timetable.htm.
The half life of Clonazepam is 19 to 90 hours or 1 to 4 days. Clonazepam may stay in the system for 2 to 8 days. Therefore, after 8 days, Clonazepam will be totally out of the system. For more information, visit http://www.ask.com/wiki/Clonazepam
For a healthy individual who have normal weight and good metabolism, Clonazepam usually stays in the system for about 2.5 to 4 days. Taking large doses over time can also alter the metabolism of this drug making it stay in your system for much longer period.