how is the last of the 72h transit VISA calculated ?

I have an Air Asia flight from Krabi (April 18th 14h25) to Kuala Lumpur (have a small 1h30 transit in Malaysia) and then another Air Asia flight from Kuala Lumpur to Beijing. I will land on April 19th at 00:50AM (during the night).
My flight back to France is on April 22 at 01:00 AM.
As you see, if you calculate the last of the transit period it will be: 72 hours and 10 minutes (difference between departure time & arrival time).

Am I elligible to the 72h VISA?
How may I be sure how the last of the VISA is calculated?
If it is based on the time I will cross the customs then I wont have any problem.

Thanks in advance for your answer.