To delay the scheduled service emails disable the "Auto-dispatch services at time of scheduling" setting on the Main Settings page.
When this setting is disabled no notifications will be sent when services are scheduled and the "Notification Status" on the "Scheduled Routes" page will show "Not Sent".
If there are any services that haven't been been finalized and notified yet then you'll see this warning message at the top of the Technician view.
When you're ready to finalize your route select the services you want to finalize and then click on the "Finalize & Notify" button. This will send any Scheduled Service Emails according to your settings.
Once you click on the "Finalize & Notify" button you'll see confirmation with the number of services and notifications that were sent.
The time for when the "1 Day Prior To Scheduled Date" and "Pre-Service Reminder" notifications will be sent will begin from the time that the service is finalized and the notification is sent.
When the "Auto-dispatch services at time of scheduling" setting is enabled (enabled by default) then any notifications will be sent at the time of scheduling without the need to finalize and send notifications later.
On the "Scheduled Routes" page the "Notification Status" for services will be "Sent".