April 16th, 2008 by depesz | Tags: , , , | 5 comments »

simple brainteaser. take no more than 30 seconds to think about it: using standard cron installed on your unix system, how often would this command be run: */57 * * * * command ? if you choose to answer in comments, please supply ...

March 21st, 2008 by depesz | Tags: , , | 10 comments »

simple brain teaser: given standard unix crontab what is the longest possible interval between calls to the same program? for example: 15 */2 * * * /bin/echo x has interval 2 hours. what is the longest possible? and how to make it?