The Nationalist Party of China in the 1920s adopted the Gregorian calendar. This is the group that the communists overthrew and they retreated to Taiwan in 1949/50. The communists never changed back... so the Chinese calendar is only used for traditional chinese events (like the chinese new year).

This is part of the period in china known as the Century of Humiliation (1839-1949)... which includes the invasions of western powers, opium wars, etc.

Unless you can point me to otherwise, I believe it is still the year 2018 of our lord and savior Jesus Christ as far as China is concerned in all of its international business and political dealings.