How do you work with the DateAdd function to add hours?

I'm new to AMPScript. I'm working with a Journey with SF Data Entry Source, specifically trying to send emails after someone registers for an event (which is logged in CRM).

I want to add six hours to the time logged in CRM, coming into SFMC via a data extension column called Event_Attendee_Enrollment__c:Event__r:Start_Time__c.

%%[ VAR @StartDate, @NewDate<br>SET @StartDate = AttributeValue(‘Event_Attendee_Enrollment__c:Event__r:Start_Time__c’)<br>SET @NewDate = DateAdd(@StartDate, 6, “H”)<br>]%% <br>%%=Format(@NewDate, “HH:mm”)=%%

But I am getting this error:

The subscriber preview failed to generate. Review the details, correct all issues, and try again. An expected comma is not found inthe varible declaration.

Script: VAR @StartDate @NewDate
ListID: 147 Index: 13286

Where am I going wrong?