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 table_23575917_6 ( first_broadcast VARCHAR, davids_team VARCHAR )

### Question ###
When david o'doherty and katherine parkinson are both on the davids team when is the first broadcast?

### Accurate SQL ###

SELECT first_broadcast FROM table_23575917_6 WHERE davids_team = "David O'Doherty and Katherine Parkinson"