The crontab syntax is popular because it has been standardized by POSIX: http://pubs.opengroup.org/onlinepubs/7908799/xcu/crontab.html http://pubs.opengroup.or

The crontab syntax is popular because it has been standardized by POSIX: http://pubs.opengroup.org/onlinepubs/7908799/xcu/crontab.html http://pubs.opengroup.org/onlinepubs/7908799/xcu/crontab.htm... In a sense, crontabs are the lowest common denominator for scheduling tasks on POSIX-compliant systems.