java/time/Clock.java

121  * The Java Time-Scale mandates the use of UTC-SLS, however clock implementations may choose
123  * Implementations are therefore not required to actually perform the UTC-SLS slew or to
144      * system clock, converting to date and time using the UTC time-zone.
153      * Conversion from instant to date or time uses the {@linkplain ZoneOffset#UTC UTC time-zone}.
156      * It is equivalent to {@code system(ZoneOffset.UTC)}.
158      * @return a clock that uses the best available system clock in the UTC zone, not null
161         return SystemClock.UTC;
174      * The {@link #systemUTC() UTC clock} should be used when you need the current instant
204         if (zone == ZoneOffset.UTC) {
205             return SystemClock.UTC;
417      * This returns the millisecond-based instant, measured from 1970-01-01T00:00Z (UTC).
428      *  the Java epoch of 1970-01-01T00:00Z (UTC), not null
485         static final SystemClock UTC = new SystemClock(ZoneOffset.UTC);
533                 // when the offset it is given is too far off the current UTC