old_contents: # -*- coding: utf-8 -*-
  import datetime
  import json
  
  
  class JSONEncoder(json.JSONEncoder):
      def default(self, obj):
          if isinstance(obj, datetime.datetime):
              return obj.isoformat()
          elif isinstance(obj, datetime.date):
              return obj.isoformat()
          elif isinstance(obj, datetime.timedelta):
              return (datetime.datetime.min + obj).time().isoformat()
  
          return json.JSONEncoder.default(self, obj)
  
new_contents: # -*- coding: utf-8 -*-
  import datetime
  import json
  
  
  class JSONEncoder(json.JSONEncoder):
      def default(self, obj):
          if isinstance(obj, datetime.datetime):
              return obj.isoformat(sep=' ', timespec='seconds')
          elif isinstance(obj, datetime.date):
              return obj.isoformat(sep=' ', timespec='seconds')
          elif isinstance(obj, datetime.timedelta):
              return (datetime.datetime.min + obj).time().isoformat(sep=' ', timespec='seconds')
  
          return json.JSONEncoder.default(self, obj)
  
subject: Fix #87: Add sep=' ', timespec='seconds' arguments to isoformat calls in encoder.py