I want to take high speed train from Hong Kong to Shenzhen on November 27 How long does it take?

There is no high-speed train service for this journey, it is HK MTR. At Hung Hom Railway Station, take local East Rail Line to Lo Wu within around 40min. Then you may need to spend around half an hour to cross the border to Luohu, Shenzhen. After that, you can transfer to local transportation to your destination in the city.