Visitng the Great Wall from Changzhi (Fri night to Mon morning)

There is one direct train K1164 at 18:40 from Changzhi Train Station to Beijing West Railway Station at 7:56am the next morning. If you visit Badaling, you can see Juyongguan Great Wall nearby or Ming tombs on the same day. Or you can have more time at Badaling and back to the city to see get around Beijing that day. I would not suggest you take the same train back to Changzhi, or it leaces at 9am in the morning and get to Changzhi at night. For alternative choice, you can take D trains from Beijing West to Taiyuan, 3.5 hours. and then take express bus from Taiyuan to Changzhi, 3 hours. If so, take D2009 at 12:12 or D2011 at 12:38 from Beijing West to Taiyuan at 15:33 or 15:58. Then take taxi to Taiyuan's 建南汽车站, there is buses back to Changzhi and last bus at 18:00. That mean you have the morning free on sunday in Beijing city. You still have time to see someplace.