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_45100 ( "Date" text, "Tournament" text, "Winning score" text, "Margin of victory" text, "Runner(s)-up" text )

### Question ###
What is Date, when Tournament, is Greenbrier Classic?

### Accurate SQL ###

SELECT "Date" FROM table_45100 WHERE "Tournament" = 'greenbrier classic'