java - Android如何在android中获取两个时区之间的时差？

Question

我需要获取不同时区的两个日期之间的时差。目前我正在这样做:

Calendar c1=Calendar.getInstance(TimeZone.getTimeZone("EDT"));
Calendar c2=Calendar.getInstance(TimeZone.getTimeZone("GMT"));
String diff=((c2.getTimeInMillis()-c1.getTimeInMillis())/(1000*60*60))+" hours";
new AlertDialog.Builder(this).setMessage(diff).create().show();

我得到 0 小时。我做错了什么？

Answer 1

getTimeInMillis() 返回 自 UTC 纪元以来的毫秒数。换句话说，时区与它无关。

我怀疑你真的想要:

long currentTime = System.currentTimeMillis();
int edtOffset = TimeZone.getTimeZone("EDT").getOffset(currentTime);
int gmtOffset = TimeZone.getTimeZone("GMT").getOffset(currentTime);
int hourDifference = (gmtOffset - edtOffset) / (1000 * 60 * 60);
String diff = hourDifference + " hours";