Datetime fields return as integers in view
This has happened because the definition of the table has changed since the view was last modified. Maybe someone altered one or more columns, or the table was dropped and re-created with columns in a different order, different types, etc.


Temporary fix: 

EXEC sys.sp_refreshview N'dbo.viewname';

Permanent fix: 


Stop using SELECT * in views (and maybe even consider always using WITH SCHEMABINDING for all views). 
I blogged about the SELECT * symptom here.
I blogged about the benefits of SCHEMABINDING here, and they include being unable to alter a table when a view is schema-bound to it.