Quick curiosity…

In regards to real time…

By convention, this function increases at a rate equal to 9192631770 times the period of the radiation emitted by the transition between two hyperfine levels of the ground state atomic cesium 133, a time unit which people have agreed to call second,

In “VerĂ­ssimo P, Rodrigues L.; Distributed Systems for System Architects; KAP; 2001