A major Toronto hospital network says its systems will be fully restored by the end of the day.

In a tweet, the University Health Network said it was confident that the system outages are not the result of a cyber attack and work overnight restored virtually all systems.

The UHN also thanked its team, which worked through the night, to ensure that hospitals can be fully operational by the end of today.

UHN issued a “Code Grey” yesterday – which is hospital code for system failure.

While the system is back online, there is a back log of data from yesterday that needs to be added today, which means patients and caregivers should expect delays at hospitals until that work has wrapped up.

The University Hospital Network, consisting of the Princess Margaret, Toronto General, Toronto Rehab, Toronto Western and the Michener Institute, the only academic institution in Canada devoted exclusively to applied health and sciences education.