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PHOTO: Stephen Brashear/Getty Images North America/Getty Images
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(CNN Business) —  

United Airlines has pushed back its flight cancellations due to the Boeing 737 Max grounding until December 19.

United (UAL) had previously canceled flights through November 3. Canceling more than 90 daily flights this far in advance will make it easier to accommodate affected passengers on different flights.

Boeing (BA) is still promising that it will have a software fix for the plane to the Federal Aviation Administration by early next month, and that it expects to win approval for the plane to fly again sometime in October. The planes were grounded in March after an automatic safety feature on the 737 Max – the company’s best-selling plane – was tied to fatal crashes in Ethiopia and Indonesia.

But it’s difficult for airlines to schedule additional flights until they know for certain that the plane is back in service. And even after that approval, it’ll take some time to add flights to the schedule. Pilots will need to get training on the new safety procedures, and the airlines will want to have a chance to sell seats on the flights they plan to add to the schedule.

Southwest (LUV), which has more 737 Max planes in its fleet than any other US airline, has canceled about 180 daily flights through January 5. American, the other US carrier with the 737 Max in its fleet, has thus far only canceled about 115 flights a day through November 2.

Boeing has said it will compensate its airline customers for the disruption to their schedules. In the second quarter it took a $5 billion after-tax charge related to paying customers.