Visit to Beijing on separate flights a few days apart

We will be flying the following schedule:

3/27 Chicago-Beijing (arrives in Beijing 5 PM 3/28)
3/29 Beijing-Tokyo (depart 4:20 PM 3/29) (almost exactly 24 hours in Beijing)
4/3 Tokyo-Beijing (arrive in Beijing 12:05 PM)
4/6 Beijing-Chicago (depart Beijing at 12 PM) (almost exactly 72 hours in Beijing)

Inadvertently, we have two stops in China that are less than 24 hours and less than 72 hours each, both very close to the limit. Do these two stops count separately as free stops, or do they add together and therefore require a tourist visa?

Thank you!