DateTime in formulas
System.DateTime.Now and System.DateTime.Today have been
added to the list of methods that are not allowed in formulas in multi-tenant
sites.If you try to save a formula that uses one of these methods, and error message is shown,
advising you to use ServerApplication.GetDateNow or
ServerApplication.GetDateToday instead.
This ensures that the time is shown correctly in the tenant site.
System.DateTime uses the timezone of the server, which might be different
from the tenant timezone.