Fire Trigger on Specific Day in Salesforce

Sample Code:

trigger AccountTrigger on Account(before update, before insert, before delete){
    
    DateTime dt = System.now();
    String today = dt.format('EEEE'); 
    
    for(Account a : trigger.new){
        
        if(today == 'Sunday'){
            
            // Process your logic.
        }  
    }
}