Shenzhen North to Hong Kong International Airport

Hi I will be arriving at Shenzhen North Railway station at 1800 on the 4th April (last day
of tomb sweeping holiday?). I wish to travel to HKI where my flight departs at 2345 hours.
What is the quickest route I can take? I have found details of a bus service between the
two which takes 3 hours. Would this service be running to its normal schedule on the
4th April.