I don't know where you have the field. If you are actually putting it on the record and using the timer, then this probably won't work. We use the related list 'time worked' and we are going to the related table and seeing if a record exists. We are not looking for an amount of time, just a record of time being recorded. So if the below related list is empty they can not resolve the incident.
no no . my requirement is not like that. i have field.
