EEM to execute a CLI Command every 15 minutes
Here is a link to a Cisco page with an introduction to EEM:
And here is another link to a Cisco page, but this one is more of a reference:
event manager applet ABCD
event timer cron cron-entry "0,15,30,45 * * * *"
action 01 cli command "enable"
action 02 cli command "config term"
action 03 cli command "....."