 Compile-Time Rational Numbers  Durations  Clocks  Time Points  Dates  Time Zones 4 Agenda  Compile-Time Rational Numbers  Durations  Clocks  Time Points  Dates  Work with rational numbers at compile time  Always normalized representation  Needed for durations in the library6 Compile-Time Rational Numbers  Define a rational number: using r1 = ratio<1'000'000'000'000'000'000, 1>;9 Agenda  Compile-Time Rational Numbers  Durations  Clocks  Time Points  Dates  Time Zones10 Durations  Interval between two points in time  Represented by std::duration