This year marks the first time since state legalization that April 20 - the unofficial marijuana

- falls on a Saturday, so retailers in markets with legal adult-use cannabis are

for what could prove a record-setting weekend.

4/20 sales set a high bar last year at $26.6 million in California, Colorado, Nevada and Washington state, according to Headset, a Seattle-based data analytics firm that specializes in cannabis.

Colorado's sales growth on 4/20 outpaced others, with a whopping 128% spike.

By contrast, California - where consumers have griped about high prices for retail cannabis - had lower sales growth at 103%, which some industry analysts blame in large part on the thriving illicit market. But

, which regulators now allow, could be a game changer that causes sales growth in the Golden State to surpass other adult-use markets.