27 Time library [time]

27.5 Class template duration [time.duration]

27.5.4 Special values [time.duration.special]

static constexpr duration zero() noexcept;
Returns: duration(duration_­values<rep>::zero()).
static constexpr duration min() noexcept;
Returns: duration(duration_­values<rep>::min()).
static constexpr duration max() noexcept;
Returns: duration(duration_­values<rep>::max()).