Which factory in Shenzhen only adds 36 hours?

Do you mean working overtime on weekdays or weekends or both? Most electronics factories in Shenzhen basically add two hours every night, one weekend and one Saturday, and then rest for about 60 hours a day. This is quite normal. If you are busy, it is rare to add extra off-season. Sometimes, it's like the five-day and eight-hour system for civil servants. If you mean all overtime 36, it's not much. You can try to find three shifts, and each shift will rest for 8 hours.