如何让PST到达mid

Question

我需要在现在和午夜之间获得美国/洛杉矶＆＃34;＆＃34; America / Los_Angeles＆＃34; （PST）。

midnightAtPST = ???;

long millis = ChronoUnit.MILLIS.between(now, midnightAtPST) ???

这就是我现在所拥有的，它给出了一个不正确的值：

LocalDateTime midnight = LocalDateTime.now().toLocalDate().atStartOfDay().plusDays(1);
Instant midnigthPST = midnight.atZone(ZoneId.of("America/Los_Angeles")).toInstant();
Instant now = LocalDateTime.now().toInstant(ZoneOffset.UTC);

long millis = ChronoUnit.MILLIS.between(now, midnigthPST);

Answer 1

Since you're interested for the time in a specific zone, do not use a LocalDateTime, which does not have the notion of timezones, but use a ZonedDateTime.

You can obtain the current date in a given zone with the ZonedDateTime.now(zone) static factory. Then, you can have the date at midnight (on the next day) in a given timezone with the method atStartOfDay(zone) on the type LocalDate.

ZoneId zoneId = ZoneId.of("America/Los_Angeles");
ZonedDateTime now = ZonedDateTime.now(zoneId);
ZonedDateTime midnight = LocalDate.now().atStartOfDay(zoneId).plusDays(1);

long millis = ChronoUnit.MILLIS.between(now, midnight);

This will correctly return the number of milliseconds between the current date and the start of the next day in Los Angeles.

Answer 2

您的方法很好，除了now时刻，您从时区转换为UTC时区，给出了您不想要的偏移。

这应该按照您的预期运作：

Instant now = Instant.now();