By Adam Hoge-

(CBS) — Happy NFL New Year.

At 3 p.m. CT today, the league calendar flips over and the 2014 season begins.

But what does that mean? Here’s everything that happens at 3 p.m. CT today:

– All 2013 player contracts expire. Players who are not under contract for 2014 become free agents.

– Free agents can begin signing with new teams.

– Top-51 begins. All clubs must be under the 2014 salary cap ($133 million) at 3 p.m. CT with the top 51 contracts counting towards the cap.

– The 2014 trading period begins. While much of the focus is on free agency, you could also see a few trades go down.

Before 3 p.m. CT, you’ll likely see more releases across the league, as well as rumors about signings and trades. The fun really starts this afternoon though, when rosters will start to fill out.

Adam Hoge covers the Bears for and is a frequent contributor to 670 The Score. Follow him on Twitter at @AdamHoge.

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