Hi @BronwynJackson - Thank you for reaching out. Unfortunately there is specific feature to give Canvas LMS a "default/scheduled" time to release marks, I would suggest investigating the Grade Posting Policy via this community article How do I use posting policies in a course? You can use posting policies in the Gradebook to manage assignment grade visibility for students. Posted grades are visible to students in your course. Hidden grades are visible to you in the course gradebook, but students cannot see them.

This can be set at the assignment or for the entire course allowing teachers to have the confidence to "post" grades at a time that makes the most sense. Enjoy!