Frontier Airlines extends to Aug. 24 free carry-on special for flights booked online

Flying Frontier Airlines just became a little less expensive. For another day, at least.

Frontier Airlines has extended to Aug. 24 a one-day only special by allowing passengers to have one free carry-on if passengers book flights by 11:59 p.m. Eastern.

The original carry-on deal expired at midnight on Aug. 23.

Carry-on fees at Frontier Airlines can reach $50 or more.

According to Frontier Airlines' policy, carry-on baggage is not included as fee free, and passengers may pay for carry-on baggage fees at the time of booking.

Carry-ons should not exceed 24 inches x 10 inches x 10 inches, including handles and wheels, and must fit in the overhead bin or under the seat in front.

What else to know about the one-day only carry-on deal at Frontier.

How to get the free carry-on deal at Frontier Airlines

Passengers must book their Frontier flight Aug. 24, either online at Fly Frontier or through the Fly Frontier mobile app.

Additionally, this deal only applies to flights between Sept. 5 and Feb. 13.

And there is a limit one carry-on per person per direction. 

"Now is a great time to snag a deal on a September adventure and we are making our already low fares extra attractive with this unprecedented one-day-only offer," said Frontier Airlines spokesperson Daniel Shurz. "With fares starting at $29 per person, plus a free carry-on bag, it’s more affordable than ever to explore new places or catch up with loved ones."

Frontier Airlines flies out of Trenton-Mercer Airport, Philadelphia International

Frontier Airlines offers several flights out of Philadelphia International Airport and Trenton-Mercer Airport daily.

For example, a roundtrip flight to Miami, booked Aug. 24 to leave from Philadelphia International Airport on Friday, Sept. 8 and returning on Monday, Sept. 11 is $76.

A similar flight from Trenton-Mercer Airport to Miami will cost $142.

Frontier Airlines offers domestic flights to more than 40 cities through Philadelphia and Trenton-Mercer Airport.

Frontier flies direct from Trenton Mercer to Atlanta, Charlotte, Fort Lauderdale, Fort Myers, Orlando, Raleigh-Durham, Tampa, and West Palm Beach.

Trenton-Mercer Airport expansion

The Frontier Airlines deal comes as Trenton-Mercer Airport is slated for a major expansion.

Trenton-Mercer Airport expansion:Trenton-Mercer Airport expansion approved by FAA. Agency forecasts 51% increase in flights

Last year, the Federal Aviation Administration approved plans by Mercer County for a modern airport, replacing the facility constructed 1975 when Trenton-Mercer averaged just 150 air passengers per day and there was no security screening at airports.

The FAA forecasts a 51% increase in flights from Mercer County, rising from 316,665 to 476,507 by the year 2035.

Rep.Fitzpatrick wants halt on expansion:Fitzpatrick asks feds to halt construction of Trenton-Mercer Airport without more study

Trenton-Mercer Airport plans to quadruple the size of its current passenger terminal and to construct a parking garage for approximately 1,040 vehicles. Currently, passengers board and de-plane on the tarmac.

One-half of the terminal space was given over to security screening after the Sept. 11, 2001 terror attacks. Baggage check for arriving flights is currently in a two-room trailers off the parking lot.