The answer is quite simple... hrs.
Quite simple but quite incorrect - in three ways in three letters
1) the international convention is that units are expressed in the singular - no s at the end - that would make it hr and not hrs
2) the international convention is that two letters are not used if one is unambiguous - that would make it h and not hr
3) the unit is defined by the BIPM (guardian of the SI units recognized everywhere but the rogue regimes of North Korea and the USA) as h
every four hours
T1.5 = Time @ 1.5 hours
24/7 sounds like 24 7
Hours can be abbreviated using the degree symbol. Minutes can be abbreviated using the single quote (apostrophe).
The abbreviation of electron is e−.
h for hours, m for minutes.
pm
pm
Hours (divisions of time)
The abbreviation for hour would be hr.
every four hours
hrs and mins, respectively.
The medical abbreviation for "every 4 hours as needed" is "q4h prn." Here, "q" stands for "every," "4h" indicates the interval of four hours, and "prn" means "as needed." This abbreviation is commonly used in medical prescriptions and notes to guide dosing schedules.
T1.5 = Time @ 1.5 hours
The medical abbreviation for every four hours is q4h.q4h
24/7 sounds like 24 7
In construction it means " Machine Usage Ratio " . It is the ratio of no. of hours for which machine worked to no. of hours for which machine was available.