Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown
General Flight Cancelled / Delayed
Environment - Non Weather Related; Staffing
Taxied onto runway after GA airplane landed; while waiting for them to exit runway our release void time expired. Had to exit runway to call for new release. There were probably at least 5 GA airplanes in the pattern or on CTAF since Tower was closed. We couldn't reach center on radios so called on phone holding short. Gave us a short release time of about 2 minutes; 39 past the hour. After the last GA plane landed I thought we had time to takeoff so we took the runway to line up. They took a long time exiting runway and our release time passed. Takeoff power was never applied; we exited the runway; taxied back to hold short and called Dispatch and then Center for a new release time.
Air carrier First Officer reported missing the IFR release time due to general aviation traffic in the pattern and the Tower being closed.