The Turnitin service, which EMU uses through Moodle, will be unavailable because of scheduled maintenance on January 5, 2019 between the hours of 11 AM and 7 PM. Turnitin is a third-party service–EMU has no control over when they perform scheduled maintenance.
Their notification about this maintenance window states:
Users will be unable to submit, grade, or access our service during this maintenance window, so please ensure that any submission deadlines are adjusted to fall outside of the window.
Turnitin provides a system status page which may contain updates about this outage.