Harkins, Cinemark and AMC are offering discounts and freebies for National Popcorn Day on Sunday. Here's how to score the deals in Arizona.

Flavacol is a popcorn seasoning salt widely used in movie theaters to create that signature buttery, salty flavor. It’s a fine, orange-yellow powder made with salt, artificial butter flavor (diacetyl), and coloring agents, which is what gives movie theater popcorn its vibrant color and rich, savory taste.

Cinemark has its own version of BYOB — Bring Your Own Bucket — on Sunday. For $5, moviegoers can fill up their own container. The only limitation is that the bucket has to be 400 oz. or less.

National Popcorn Day deals include half off popcorn, free popcorn, size upgrades and even all-you-can eat popcorn at participating theaters.

Cinemark Theatres is celebrating National Popcorn Day by offering to fill any container full of popcorn for $5.

The “Bring Your Own Bucket” day event kicks off Sunday, Jan. 19, at participating Cinemark locations nationwide on National Popcorn Day, according to the Texas-based theater chain. For $5, customers can fill up their choice of container, Cinemark said. No movie ticket purchase is required.

The Cinemark movie chain plans to serve up a massive amount of buttery goodness during National Popcorn Day in January.

National Popcorn Day is one of the best days of the year at Cinemark, and for popcorn lovers everywhere. We are thrilled to mark this year’s celebration with our first ever B