Mysql Logs automatically deleted after 3 days

/* 3 days in seconds days variable is a depcreted var dont use it */
SET GLOBAL binlog_expire_logs_seconds = 259200; 

/* if you want to delete right away */
/* delete all the logs older than 3 days */
PURGE BINARY LOGS BEFORE DATE(NOW() - INTERVAL 3 DAY) + INTERVAL 0 SECOND;