My regular hours are from 9am to 5pm US Pacific time every weekday.
I do take time off for US holidays and now and then for vacations.
The best way to reach me at any time is by emailing the Shopify support address (shopify at this domain). That will help me keep track of your email and respond once I'm available again.
Feel free to see if my self-service Knowledge Base has an answer for you. Unlike me, it works 24/7.