User Configuration > Administrative Templates > Microsoft Project 2016 > Project Options > View
User
HKCU\software\policies\microsoft\office\16.0\ms project\options\view
Specifies the format for displaying dates. Some information, such as time formats and the date separator, is set through the Control Panel. If you enable this setting, dates are displayed in the format you set. If you disable or do not configure this setting, the user's default setting is used.