Would I be eligible for the 144 hour transit visa in Shanghai?

Hi i'm a UK passport holder and looking to fly to Shanghai in July with Qatar Airways with a short transit in Doha. I would arrive in on the 13th of July 2016 at around 16.20 in the afternoon. Firstly a 144 hour free tourist would begin from the 14th of July at 00.00 is that correct? Meaning I would need to leave Shanghai by the 19th of July 23.59? Is that correct?

I plan to book a ticket with spring airlines to go from Shanghai to Hong Kong before the 144 hour free transit would expire in Shanghai. A UK passport holder doesn't require an entry permit for Hong Kong. I would stay in Hong Kong for a few days and I would then take an Air Asia flight to Thailand and my return Qatar Airways flight would be from Bangkok.

Thanks in advance.