title: strptime() argument 1 must be string, not type Django
body: <p>I'm having trouble figuring out where I went wrong with this app trying to validate that a date is either in the present or future. But I'm getting the error in question.
  Here is the error:</p>
  
  <pre><code>class AppointmentManage(models.Manager):
      def appointvalidate(self,postData):
          errors={}
          pause=datetime.datetime.strptime(time,"%Y-%m-%d %H:%M")
          if len(postData['task'])&lt;2:
              errors["Task field cannot be left blank"]="task"
          if len(postData['task'])&lt;20:
              errors["Task field is too long"]="task"
          if len(postData['date'])&lt;1:
              errors["Date field cannot be left blank"]="date"
          else:
              print "this is pause "
              print pause
          if pause&lt;datetime.datetime.now():
                  errors["Only present and future dates are permissable"]="date"
          if len(postData['time'])&lt;1:
              errors["Time field cannot be left blank"]="time"
          return errors
  </code></pre>