Schedule Apex Class for Different Hours.

Here is the codes to run in the Developer console for Different Hours :

For Every 1 Hour : 
System.schedule('Schedule Job', '0 0 1,2,3,4,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23 * * ?', new ApexClass());

For Every 2 Hour : 
System.schedule('Schedule Job', '0 0 2,4,6,8,10,12,14,16,18,20,22,23 * * ?', new ApexClass());

For Every 4 Hour : 
System.schedule('Schedule Job', '0 0 4,8,12,16,20,23 * * ?', new ApexClass());