[time.clock.cast.sys.utc]

# 30 Time library [[time]](./#time)

## 30.7 Clocks [[time.clock]](time.clock#cast.sys.utc)

### 30.7.10 time_point conversions [[time.clock.cast]](time.clock.cast#sys.utc)

#### 30.7.10.3 Conversions between system_clock and utc_clock [time.clock.cast.sys.utc]

template<>struct clock_time_conversion<utc_clock, system_clock> {template<class Duration> utc_time<common_type_t<Duration, seconds>>operator()(const sys_time<Duration>& t) const;};

[ð](#lib:operator(),clock_time_conversion)

`template<class Duration>
  utc_time<common_type_t<Duration, seconds>>
    operator()(const sys_time<Duration>& t) const;
`

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/time.tex#L3698)

*Returns*: utc_clock​::​from_sys(t)[.](#1.sentence-1)

template<>struct clock_time_conversion<system_clock, utc_clock> {template<class Duration> sys_time<common_type_t<Duration, seconds>>operator()(const utc_time<Duration>& t) const;};

[ð](#lib:operator(),clock_time_conversion_)

`template<class Duration>
  sys_time<common_type_t<Duration, seconds>>
    operator()(const utc_time<Duration>& t) const;
`

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/time.tex#L3720)

*Returns*: utc_clock​::​to_sys(t)[.](#2.sentence-1)
