Beijing time is East Zone 8 and Washington time is West Zone 5. In order to avoid crossing international date line, we can calculate from Beijing to the west. Beijing is 8-(-5)= 13, which means that Beijing is 13 hours earlier than Washington. Therefore, when Beijing time is 8 am, Washington time is 8+24- 13= 19 of the previous day.

On the issue of crossing the date line, we can choose a detour, so that there will be no problems because of the date.