DENVER (KDVR) — Around 840,000 people are expected to pass through security at the Denver International Aiport in the 12 days between Friday, Nov. 17, and Tuesday, Nov. 28.

Because of this, the Transportation Security Administration is warning Denverites of what they can expect and things they should know ahead of time.

What you can expect at DIA

TSA gave some information on what you can expect when you travel through DIA.

Security at DIA is usually busiest between 4 a.m. to 10 a.m. and from 1 p.m. to 6 p.m.

However, TSA said there are more flights leaving after 8 p.m. than usual, so travelers should expect the security lines to be busier at that time as well.

There are two primary checkpoints at DIA that people can choose from, and both offer different types of screening.

The North Security Checkpoint is primarily for TSA PreCheck passengers and is open from 4 a.m. to 7:45 p.m. There are only a small number of standard lanes for people without TSA PreCheck.

The South Security Checkpoint is primarily for people without TSA PreCheck. This checkpoint is open all day, every day. There are some TSA PreCheck lanes, but those close at 5:45 p.m. According to a release from DIA, PreCheck passengers traveling after 6 p.m. may also use North Security until 7:45 p.m. or they can receive expedited screening after 8 p.m. through the standard lanes at this checkpoint.

There is also a third checkpoint at the A-Bridge that is open from around 4:30 a.m. to 5:45 p.m. and is only for people without TSA PreCheck.

The airport also offers a reservation service at the A-Bridge checkpoint from 5 a.m. to 5 p.m. It allows people to reserve a time to go through screening.

The three busiest days at DIA were expected to be Tuesday, Nov. 21, Wednesday, Nov. 22, and Sunday, Nov. 26.

That Sunday in particular was expected to be the busiest day of the holiday travel period, with TSA predicting that around 86,000 people would go through security at DIA that day.