Regional Jet 200 ER/LR (CRJ200)
Flight Crew Air Transport Pilot (ATP)
Fatigue
No Specific Anomaly Occurred All Types
Flight Crew Became Reoriented
Human Factors
When I woke up early this morning I felt really tired; more than usual; and when I got to the airplane I found it really hard to stay focused on doing my duties. This is day five (5) for me. I picked this trip up out of open time which would have put me at 8 days off total for the month but I thought I could have completed this trip having one (1) day off and then finishing the month with a four (4) day trip. The Captain asked about my schedule and agreed that I was not fit for duty; in the last week I had about an average of 5 hours of sleep per night.  The Captain and I completed the flight with no errors or threats. I've learned that I have to manage my rest and sleeping patterns better.
CRJ-200 First Officer describes fatigue accumulated over a month of flying due to insufficient time allocated for sleep. The First Officer did not remove himself from the trip although he believed he was not fit for duty.