global class OldRecordDeleteBatch implements Database.Batchable<sObject> {
    global Database.QueryLocator start(Database.BatchableContext bc) {
        Date threeDaysBefore = System.today().addDays(-3);
        String SOQL = ‘SELECT Id FROM Employee__c WHERE CreatedDate = : threeDaysBefore’;
        return Database.getQueryLocator(SOQL);
    }
    
    global void execute(Database.BatchableContext bc, List <Employee__c> listEmp) {
        delete listEmp;
    }
    
    global void finish(Database.BatchableContext bc) {
    }
}