Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE movie ( mid number, title text, year number, director text )
TABLE: CREATE TABLE reviewer ( rid number, name text )
TABLE: CREATE TABLE rating ( rid number, mid number, stars number, ratingdate time )

### Question ###
What are the different names of all reviewers whose ratings do not have a date field?

### Accurate SQL ###

SELECT DISTINCT name FROM reviewer AS T1 JOIN rating AS T2 ON T1.rid = T2.rid WHERE ratingdate = "null"