code: def ewsformat(self):
          
          if not self.tzinfo:
              raise ValueError('EWSDateTime must be timezone-aware')
          if self.tzinfo.zone == 'UTC':
              return self.strftime('%Y-%m-%dT%H:%M:%SZ')
          return self.replace(microsecond=0).isoformat()
docs: ISO 8601 format to satisfy xs:datetime as interpreted by EWS. Examples:
              2009-01-15T13:45:56Z
              2009-01-15T13:45:56+01:00