How to trigger email by comparing date value in node? I'm using Drupal 7, with Rules and Rules Scheduler.  

I have a content type "Tutorial Class", with fields as below:


Class Date and Time 
Feedback requested (Radio button: Yes/No, default
is no)


I would like to create a Rule, so that whenever the cron runs, it will check on all "Tutorial Class" content type.  

If current time is larger than "Class Date and Time" field, and "Feedback requested" is no, an email will be triggered and "Feedback requested" will be changed to Yes.  

Currently I know how to trigger email after "Tutorial Class" is created, but I can't get the above Rule done.  

Any idea of how to set this rule?
Hi You can add a filed in your content type like date_content_type .
a)chose filed type =date  in content type(admin/structure/types/manage/content_type/fields)

b)add a condition in Rule set 
c) select condition= data comparison
d) click on continue button
e) select data selector set your custom date type field 
f)then add your time() value and save it . now your date condition rule set will be execute 
i hope it will help you 
Thanks