Function operator-

util/datetime/base.h:691–693

} // namespace NDateTimeHelpers

constexpr TDuration operator-(const TInstant& l, const TInstant& r) noexcept {
    return TDuration::FromValue(::NDateTimeHelpers::DiffWithSaturation(l.GetValue(), r.GetValue()));
}

constexpr TInstant operator+(const TInstant& i, const TDuration& d) noexcept {
    return TInstant::FromValue(::NDateTimeHelpers::SumWithSaturation(i.GetValue(), d.GetValue()));