Recurring Tasks Extension

Initially, I was getting some errors like PHP Fatal error: Uncaught Error: Non-static method ACLRole::getAllRoles() cannot be called statically. So I gave static keyword to the method getAllRoles in ACLRole.php file and then only I can able to create or view the recurring tasks inside recurring tasks extension. Now the I can able to create recurring tasks but when I select any of the options like daily, weekly, monthly., Execution time is not appearing. I am in need of your help you to resolve this issue.