If you would like your automation to only execute if a condition is satisfied within a certain time range, you can do so by clicking “Valid Time Period" within the Smart Automation's Settings.
Default is set to execute the automation if condition is satisfied 24 hours a day/7 days a week; change this to your desired time range. Click 'repeat' to select only certain days you'd like the automation to be valid within. If the conditions of the Automation are satisfied during your specified time period, the automation will execute. If the conditions of the Automation are satisfied outside the specified time range, the Automation will not be triggered.