Go out and take his favorite treats and call. Ask your neighbors to check their garages - sheds - under stairs - decks and bushes. He's probably hiding somewhere close and feeling scared and confused. Ask your neighbors to check more than once - cats are very good at hiding. Check at night late when it's quiet as that's when he may feel safer to come out.
Put out his dirty cat box and some of your worn clothes. The scent will help him find home.
Go out at night when it's quiet and take her favorite treats. Call him softly and listen for soft meows back - especially near garages and sheds he may have become trapped inside. Take a flashlight and look under bushes and other hiding places for reflective cat eyes.
Ask your family and friends to help you make posters and put them up all over your neighborhood - especially near stores and your community center.
Call Veterinary clinics and animal shelters in case someone brought him in or called about spotting him.
Post on YYC site too - they have a very large following.
Don't give up - keep looking especially at night. I hope you find her soon. I'm sharing.
Please post in YYC group too. They have a very large following. The more people looking for your kitty the better.