You can set up two different email notifications via Dispatch'r that need to be sent out during your Business hours and Non Business hours. Move to Admin--> Email notifications--> Requester notifications--> New ticket created notification needs to be turned off.
Navigate to Admin--> Dispatch'r--> Create new rule.
Condition: "Created" "during" "Non business hours"
Action : Send email to requester
Another Dispatch'r rule needs to be created for the new ticket created notification for tickets created during business hours.
Condition: "Created" "during" "Business hours"
Action : Send email to requester