What are the best, and worst, times to fly out of Newark?

Air travelers looking to leave Newark Liberty International Airport on time should book their flights in the first half of the day, according to a report commissioned by the U.S. Department of Transportation that looked at departure times across 29 major U.S. airports during March 2016.

The 6 a.m. (6 to 6:59 a.m.) and 7 a.m. (7 to 7:59 a.m.) hours were Newark's most efficient, with on-time departures 93.3 and 92.1 percent of the time, respectively. In fact, through the 1 p.m. hour, on-time flights departed at an 86 percent clip or better.

But starting with a dip to 79.7 percent at 2 p.m., the report showed that Newark failed to maintain that efficiency throughout the rest of the day, ending with an overall 82 percent on-time mark. That was still higher than the average of 81.3 percent of flights leaving on time in March at these 29 locations.

Newark ranked 15th out of the 29, scoring lower than the national average for every hour from 4 p.m. through 10 p.m.

"On-time" was defined in the report as 15 minutes or less than the scheduled departure time.

Newark did perform better than John F. Kennedy International Airport (80.7 percent on time) and LaGuardia Airport (77.4) during the month, although LaGuardia registered one of the few perfect hours in the report: 100 percent of flights left on time between 10:00 and 10:59 p.m. That time, ironically, was Newark's worst, with just 62.7 percent on-time departures.

Flights at Philadelphia International Airport departed on time at a rate of 84.2 percent in the month.

San Francisco International Airport scored the lowest in the USDOT report, with only 71.8 percent of its flights leaving in a timely fashion in March. The worst-performing single hour for any airport was the 6:00 to 6:59 p.m. timeframe at Salt Lake City International Airport, during which only 41.7 percent of flights departed on time. Salt Lake City, however, finished first overall (87.6).

NJ Advance Media reported Tuesday that 12 members of New Jersey's congressional delegation have signed a letter sent to Transportation Security Administration Administrator Peter Neffenger, asking for updates on ways the TSA plans to take steps to reduce wait times at Newark.

Patrick Lavery produces "New Jersey's First News" and is New Jersey 101.5's morning drive breaking news reporter. Follow him on Twitter @plavery1015 or email patrick.lavery@townsquaremedia.com.