Hi 
I need to update regularly a field value. 
How to run this action daily ? 
I do not find any scheduler.

Many thanks

If I put only  
<apex:page standardController="Case"> xxxxx </apex:page>
the Visual Force page is displayed only on Layout dedicated to the Case .

I tried with this without succcess
<apex:page standardController="Case Close"> xxxxx </apex:page>
Never displayed on Case Close Page Layouts. 

Is there any possibility ? 
Thanks