Cheech & Chong, who joke that they're on a senior stoners tour, are offering half-price tickets today for their Mary 28 show at the Waikiki Shell.

The discount is in honor of today's date: 4-20.

The legendary comedy duo's tour is officially called "Cheech & Chong Light Up America."

The discount is from 10 a.m. to 10 p.m. today through www.ticketmaster.com. Discounts are limited to four per order and can be purchased by using the password "420."