Does the lay over time counts from 00:00 clock on the following day of arrival?

Hi , about 144hr transit free China visa exemption, . Eg if I arrive Shanghai on 5 January 7am, the lay over time starts from 00:00 clock of 6 January? If I stay in Shanghai from 5 January 7am to 11 January 2019 7:55pm, does that mean the total period equals to 140 hours of my stay ? My cruise company only accept abt 144 hr free transit visa exemption but not about how to calculate the lay over time. Without calculating the overtime then my stay will be over 144 hours. What can I do? Please guide me what I can do. Thank you