Keith in Staten Island pointed out that I did not answer half the question last week: when to practice Tai Chi at night. So here goes the rest of the story, as the evening round of Tai Chi has some special points to it to consider, as well.
Professor Cheng said that Tai Chi should be the first thing you do in the morning andthe last thing you do before going to sleep. So Tai Chi should bracket sleep.
This is good information if you are awake until you put your head down on the pillow. This is good information for some one like my wife. I get tired and just before I go to bed, I am too tired to do the Tai Chi correctly. So I allot a half hour to an hour earlier in the evening, when I am done interfacing with the rest of the world and at rest from the activities of the day, and practice then. I do several rounds of form and practice some standing postures. Then I go off to bed and being a modern American, watch some TV till sleep overtakes me.
There are some guidelines to knowing how you are doing in your daily activities, and in your sleep, as can be seen in your Tai Chi.
If you awake, and practice and you become sleepy after, you did not sleep well. If you slept well, after your practice, you would be bright eyed and alert for the day
If you practice at night and it wakes you up, you had a tense day, but not a physically demanding day and you body is awakened by the Tai Chi. If your body is tired, your practice will make you very sleepy.
In each case, morning and night, if you are tense, it will show in your state being the reverse of what you want it to be. sleepy in the morning and awake at night.
If you have had a good day, and a good sleep, you will be alert in the morning and sleepy at night.
Enjoy your practice.
In Tai Chi,
Bill