DateTime and ISO 8601

ISO 8601 uses the 24-hour clock system. As of ISO 8601-1:2019, the basic format is T[hh][mm][ss] and the extended format is T[hh]:[mm]:[ss]. ... [hh] refers to a zero-padded hour between 00 and 23. [mm] refers to a zero-padded minute between 00 and 59.