We have an option in gmail : Vacation Responder , Just turn on Vacation Responder and there you have this feature set !
1. To find vacation responder , find settings option in your gmail account as below :
2. In settings scroll down and find "Vacation Responder" , set the date range and you have it all set.
Note : Also you can set auto reply for people in contact only , this will help you prevent email to unknown or spam mails !
