B737 Next Generation Undifferentiated
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 151; Flight Crew Type 3812
Communication Breakdown; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
General None Reported / Taken
Aircraft; Equipment / Tooling; Company Policy
While on the gate we received an ACARS message that we would need to extend our [Out of Duty] time if we were going to continue the flight. We responded and said we would extend our [Out of Duty] time. We received an ACARS message that our new [Out of Duty] time is XA:12z. We continued the boarding process and then pushed off the gate at time XW:24Z. We taxied to Runway 18L for takeoff. We sat there for 5 minutes and then got cleared for takeoff. On the takeoff roll we received an ACARS message which we did not responded to because that is a critical phase of flight. After we were airborne we pulled up the ACARS message and it said that if we were not off the ground by XW:12Z we would need to return to the gate. My concern is that those are two contradicting messages. One says our [Out of Duty] time is XA:12Z the other says if not off by XW:12Z return to the gate. I personally think that our [Out of Duty] messaging system or process needs to be looked at.
B737 Captain reported the flight crew did not receive an important message via ACARS from the company until airborne.