My flight lands in Guangzhou Baiyun International at 1am on Saturday in July. I had intended on getting to Shenzhen by train, but I don't know if its possible. I don't read Chinese Mandarin, so I've only been able to use what Rome2Rio has provided.
Is it still possible to get to Shenzhen at that that time of day?
You can search Chinese train schedules in English at http://trains.china.org.cn/. However, for Guangzhou-Shenzhen, I wouldn't even bother: there are trains every 10 minutes or so, and the travel time is just over an hour. Just catch the subway (Line 3) from the airport direct to Guangzhou East station and take the next train from there.
The only catch is that you're landing in the middle of the night, the first fast train from GZ East to Shenzhen is at 6:15 (although there are slow ones from GZ "main" station from 4:11) and the subway doesn't start running until 6 AM. I'd probably crash at a hotel near the airport and get going in the morning if I were you.
You've probably already visited in July and now its 6 months later but in case anyone is wondering...
Guangzhou East to Shenzhen (Luohu - the border) 广州东-深圳罗湖is a little over an hour at the DongChe 动车 speed
Guangzhou South, really far down there but on a subway line, connects to Shenzhen North in a little over 30 mins. 广州南-深圳北.
One of these is right for you, depends on your specific destination in GZ and SZ I guess.
---------If you're feeling lucky, run through the gate at the last second before boarding closes and scream 补票 bu piao and you can pay for your ticket once you get on the train with the conductor in the 餐车 eatery car. I've seen multiple people on multiple occasions (and myself) pay for their full fare full length ticket while on the short train ride
