Table schema:
CREATE TABLE table_13079788_3 (date VARCHAR, gtc_winner VARCHAR, gt3_winner VARCHAR)

Question: what are all the date for gtc winners graeme mundy jamie smyth and gt3 winners hector lester tim mullen
SQL: SELECT date FROM table_13079788_3 WHERE gtc_winner = "Graeme Mundy Jamie Smyth" AND gt3_winner = "Hector Lester Tim Mullen"