Taijiquan was designed to be trained every day regardless of mood.
The best time to train is shortly after you get out of bed.
Even half-asleep, you can work through most of your qigong and be onto the Long Yang form before you realise it.
Over time, this habit of getting up and getting on with the practice become deeply ingrained.
Like going to work.
Like brushing your teeth.
Like flushing the toilet after using it.