Don’t miss the fun on Friday, October 27th. For a fun, safe Halloween event, children and their parents are invited to Trick-or-Treat up and down Mt. Diablo Blvd. TRICK or TREAT STEET will take place from 4:00pm – 6:00pm in boo-tiful Downtown Lafayette. Dozens of participating businesses will display a poster and have balloons at their door. Trick or Treating is for children 9 and under.