[time.clock.tai.members]

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

## 30.7 Clocks [[time.clock]](time.clock#tai.members)

### 30.7.4 Class tai_clock [[time.clock.tai]](time.clock.tai#members)

#### 30.7.4.2 Member functions [time.clock.tai.members]

[ð](#lib:now,tai_clock)

`static time_point now();
`

[1](#1)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/time.tex#L3087)

*Returns*: from_utc(utc_clock​::​now()), or a more accurate value of tai_time[.](#1.sentence-1)

[ð](#lib:to_utc,tai_clock)

`template<class Duration>
  static utc_time<common_type_t<Duration, seconds>>
    to_utc(const tai_time<Duration>& t) noexcept;
`

[2](#2)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/time.tex#L3100)

*Returns*: utc_time<common_type_t<Duration, seconds>>{t.time_since_epoch()} - 378691210s

[*Note [1](#note-1)*: 378691210s == sys_days{1970y/January/1} - sys_days{1958y/January/1} + 10s â *end note*]

[ð](#lib:from_utc,tai_clock)

`template<class Duration>
  static tai_time<common_type_t<Duration, seconds>>
    from_utc(const utc_time<Duration>& t) noexcept;
`

[3](#3)

[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/time.tex#L3120)

*Returns*: tai_time<common_type_t<Duration, seconds>>{t.time_since_epoch()} + 378691210s

[*Note [2](#note-2)*: 378691210s == sys_days{1970y/January/1} - sys_days{1958y/January/1} + 10s â *end note*]
