The closing time of Yuanmingyuan is 7 pm.
Peking University has no time limit.
Suggestion:
First stop, the Summer Palace. Depart at 6 o'clock in the morning, take Line 6 at Dongsi Station, transfer to Line 4 at Pinganli Station, and arrive at the North Palace Gate of the Summer Palace.
The Summer Palace in the morning is very quiet and has another pure beauty.
At noon 1 or so, come out at the North Palace Gate, take Line 4 and arrive at Yuanmingyuan. Suggest coming out around 4 o'clock.
In the afternoon 16, take Line 4 at Yuanmingyuan Station, arrive at Dongmen Station of Peking University, and visit Peking University.
After that, take the East Gate Station of Peking University, take Line 4 and return on Line 6.