I hope to travel to China as a tourist from 6th April-24th May 2018 (49 days).

If I apply for a 3month tourist L type I am assuming that I would apply no earlier than 24th February - which will be valid until 24th May - ie covers my whole trip?

Also, Is there a six month visa that I can apply for sooner, as this would get my visa sorted, and cover me for the whole of my trip now