I don't remember exactly what time of year it was - I do remember that it was in the time between September 1985 and April 1986, because I remember the Texans upstairs, and they were there in my second year in Tianjin.
It was either Fall or Spring - not midwinter, for reasons that will become clear in a moment.
I had gone to bed, but had been restless and unable to sleep. Gradually, I became aware of a growing sound, the mutter of a crowd of people. It grew. The sound swelled, so that I had the impression of large numbers, doing something in unison. To be honest (this was China, after all) I was a little afraid; who knew that it might not be some kind of uprising, or a return of the Red Guards?
I got out of bed and went to the window, but my room was only on the second floor, not high enough to be able to get a good view. At the open window, the sound of voices was even louder and was getting louder still all the time. I discovered that I was not the only person disturbed by the noise. My Texan colleagues, two floors up, were out on their balcony and could see what was going on. A few streets over, there was a football field, between the campuses of Tianjin University, where we were, and Nankai University next door. The Texans could see that the football field was full of people, and they were all looking up into the sky. We looked up, and saw that the moon was half swallowed by shadow.
Whether all the people were participating in some kind of ritual in praise of the moon, or chanting to bring it back, or whether it was simply a well-publicized gathering to share binoculars or telescopes or something... we never learned, and I'll never know. But that crowd of people lent enormous weight and ritual to what is, after all, rather a miraculous event - the disappearance and reappearance of our moon.