If you would like to customize the time of day that your automated emails are sent you can do that by following these steps:
From the main menu click on Marketing » Preferences.
Scroll down to the Automated Email Time Preference option.
Choose your time from the drop down box and click Save.
The automated emails affected by this setting include the following:
Scheduled Gallery Invitations, Gallery Expiration Reminders, Invoice Reminders, Contract Reminders, Discount Day & Scheduled Sale Notifications