Magento how to configure cron

i have configured a custom cron in one of m开发者_StackOverflowy modules, i want it be executed every 1 week, at 11:00 am, i've wrote this in my config.xml

<cron_expr>0 0 * * 1</cron_expr>

this execute the function every 1 week at midnight, or at least this is what i understand, but now i don't know how to write the expresion to be execute at 11:00 am, i even don't know what really means the * * * * *, in the magento's wiki say everytime the cron is execute.

how can it make my cron execute every 1 week at 11:00 am

thanks

You need to configure the hour item (the second item):

<cron_expr>0 11 * * 1</cron_expr>