Broadcasters looking to participate in the upcoming spectrum auction will have just 32 hours to lock in their station commitments, the Federal Communications Commission said Thursday.

In a public notice, the FCC said broadcasters will have from 10 a.m. March 28 to 6 p.m. March 29 to declare which stations they intend to put up for sale in the auction.

Broadcaster decision must be recorded in the FCC’s “commitment module,” the commission said.

The FCC stressed the importance of quick decision-making in its notice, noting that late commitments will not be accepted. Participants who fail to submit their initial commitments during the FCC’s window will be left sitting on the auction sidelines.

The FCC recommended broadcasters make sure they can access and familiarize themselves with the module during a preview period scheduled to begin 10 a.m. March 24. The commission said technical support will be available to resolve any access issues ahead of the commitment window’s opening.

The preview period will also give broadcasters the opportunity to review a list of stations for which they make initial commitments as well as the relinquishment options for each station.

The FCC said an online tutorial and user guide for the initial commitment module will be made available on Feb. 29.

According to the FCC, the initial clearing target and band plan for the auction will be announced three to four weeks after the initial commitment deadline.

The incentive auction may include as many as 12 blocks or as few as two in one of eleven different band plans, depending on the amount of spectrum available and demand.