Days per month
Supported on: At least Windows Server 2008 R2 or Windows 7
Registry
HKCU
software\policies\microsoft\office\16.0\ms project\options\calendar Options
default days/month decimal
- range 0-100 Description
Defines the number of days that you want Project to assign to a task when you enter a duration of a month. If you enable this setting, month-long tasks will be assigned the number of days that you specified. If you disable or do not configure this setting, the user's default setting is used.