Some indicated that they were told that the problem was related to crew scheduling.

The extent of the issue or its duration was not immediately clear. Tweets referencing hours-long flight delays at GoJet were first posted on Dec. 1 in the afternoon and continued into Dec 2.

Stacey Ross, a spokeswoman for GoJet, said that a “cutover to a new computer system led to a number of delayed and cancelled flights on December 1.” Neither Delta or United returned requests for comment before.

For a complete rundown of all of the technical glitches that have plagued US aviation this year, visit Quartz’s dashboard.

Update (7:30pm ET): Added comment from GoJet spokeswoman.

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