zen cart store quick checkout fix needed - urgent

Upon checkout the store is adding a month to the "pick up" time of an order (see screen shot). This was working fine until the store owner deleted a pickup location and time and then added another. I need the month removed and made sure that she can add or delete without issues going forward. Obviously a bug has surfaced when editing this information. You must be available weekends in case something happens after fixing this because the store is live and can't afford down time if another problem emerges from the adjustment. Budget $30 and future ongoing maintenance of the site to the right person.