Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 193; Flight Crew Total 9500; Flight Crew Type 4500
Communication Breakdown; Confusion; Fatigue; Workload
Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Other / Unknown
Flight Crew Became Reoriented
Company Policy; Human Factors
We began our trip with a normal morning flight.  Our report time was XC00 and I was able to get a full night sleep at home prior to going to work.  Upon arriving in ZZZ; we were supposed to then rest at some point during the 13 hours we were in the hotel before departing again that night for a redeye segment that left at what would be XA:00am on our body clocks (Eastern Time).  It was simply not possible to get adequate rest given my inability to just fall asleep at any time during a day.  I was able to get about 2 hours of sleep prior to this ANF segment.Upon reporting for duty; the captain and I agreed that we were OK to fly what was a relatively short segment to ZZZ1.  When we arrived at ZZZ1; we were both exhausted.  I was able to fall asleep for about 2 hours upon reaching my hotel room that morning; which ended up being approx XG00-XI00 eastern time.  I was unable to force myself to sleep any further that day prior to our report time that evening.About half way from ZZZ1 toZZZ2 I realized that I was nodding off; making mistakes on ATC communications; and was generally unable to function at an appropriate level due to fatigue resulting from the unworkable rest periods leading up to this segment.  My situation degraded further as the flight continued and we entered the descent approach phase; which was approx XT00 eastern time.  I made multiple mistakes communicating with ATC.  I had a very difficult time remaining alert at even a basic level.  Complicating the situation was the fact that it was night time; we were landing in ZZZ2 where there are special procedures; short runways; prohibited areas and it was quite windy.
A B-737 First Officer was unable to adjust to the demands of his schedule which required him to sleep during the day before departing for flights during the night. He reported fatigue resulting from the unworkable rest periods making mistakes on ATC communications. He was also nodding off.