The date of this Revision. 
   Namespace:   Autodesk.Revit.DB  
  Assembly:   RevitAPI  (in RevitAPI.dll) Version: 2015.0.0.0 (2015.0.0.0) 
  Since:  2015 
Syntax
Remarks
 The Revision date is an arbitrary String and can be blank. Revit will not attempt to interpret it as an actual date. 
 Exceptions
| Exception | Condition | 
|---|---|
| Autodesk.Revit.Exceptions ArgumentNullException | When setting this property: A non-optional argument was NULL | 
| Autodesk.Revit.Exceptions InvalidOperationException | When setting this property: This operation cannot be performed on Revisions that have already been issued. |