Which postmortem parameter is fixed by 8 hours?

Algor mortis is the change which is an immediately sign of death. It involves the cooling of body. The body temperature decreases as the body after death looses the control over the circulation and exchange of gases and the control over the homeostasis. The temperature decreases until the body attains equilibrium with the external environmental temperature. The postmortem cooling or algor mortis gets fixed by 8- 10 hours after death. The temperature of the body after death can be used to determine the time since death. This can be measured by determining the temperature of the rectum which is proved to be most accurate or any other orifice such as nasal, ear and vaginal can also be used.

i just calculated it all out, and not including weekends, and all the different days off. as of this school year (2018-2019) students are spending 2198 hours in school this year