One of my BILs work with a US company selling used cisco. He is based here in Malaysia and due to it, he works when we sleep and he sleeps when we work.
I am also working with a US company. Our time difference is 12 hours. My 9pm is their 9am. So I start work from 9pm till 2am. Due to the flexibility of my job, I can do my work during my time and only need to be online at that time if I need to communicate with them during those hours.