How to add same subject twice in custom diary system?

How to setup permission for student dashboard like student should view all the subject update of there registered class and section in diary system?

I have created custom school diary system in frappe so here I am unable to add same subject twice how to overcome from this problem? For example in one week any one day one subject had two periods means the respective teacher should update regrading about that two class in diary system separately so here i am not able to add same subject update twice in my custom doctype.

@Bhavana_C_R Hi,
You are trying to create a ID by using your own naming format. You have to make that ID unique by using date and time and then you’ll not face this issue.
For example : right now your ID is Daily Update Class 8 C. So, make it something like Daily Update Class 8 C {datetime}.