如何在不同的时区获取 LocalTime？

Question

I understand that LocalTime is time-zone agnostic. But I would like to get hours in Central Standard Time (CST). All I am given is time in String:

String start = "11:00" //11 am CST. 
LocalTime startTime = LocalTime.parse(start);

This is good but server is running in different time-zone. So it will interpret it as 11 am UTC. I want LocalTime to be in CST. I need to in CST so I can invoke LocalTime.isAfter methods.

LocalTime currentTime = LocalTime.now();
boolean afterEleven = currentTime.isAfter(startTime);

Answer 1

LocalDateTime.now() is actually a shortcut for LocalDateTime.now(Clock.systemDefaultZone()) , where Clock.class represents some date-time instant ( see docs ), and static method systemDefaultZone() returns the date-time instant of your PC.

In your case it's possible to use "clock" for a different zone (zone with id="CST" doesn't exist but you can choose "America/Chicago" instead - see explanation in this answer ).

LocalTime currentTime = LocalTime.now(Clock.system(ZoneId.of("America/Chicago")));

UPD Didn't understand the task properly. In this case it's actually easier to convert currentTime instead of startTime to needed zone.

LocalTime currentTime = LocalTime.now(Clock.system(ZoneId.of("Europe/London")));

or, as Ole VV reminded:

LocalTime currentTime = LocalTime.now(ZoneId.of("Europe/London"));

then you can compare it with unmodified startTime (in this case - 11:00)