From: Upcoming change to the release schedule for non-security updates | Office Updates
We want to let you know about an important change coming to the release schedule for Office updates so that you can plan accordingly. Until now, both security and non-security updates have been released on the second Tuesday of each month. Starting in April, the non-security updates will be released in Microsoft Update and the Windows Server Update Service (WSUS) on the first Tuesday of the month, which is April 5 in this case. This will include all updates that have the Critical or Definition classification. Updates with the Security classification will continue to release on second Tuesday as usual.
This change applies only to the MSI version of Office. Office Click-To-Run (C2R) will release on second Tuesday.
Tags: Office Office 2003 Office 2007 Office 2010 Office 2013 Office 2016 Office Public Update Public Update Security