How can I convert Java ZonedDateTime to OffsetDateTime with default time zone offset?

Question

Say I have a ZonedDateTime of 2018-10-30T18:04:58.874Z : How can I convert this to OffsetDateTime 2018-10-30T13:04:58.874-05:00

I'd prefer the offset to be the default/system offset, for example pulled from OffsetDateTime.now() .

Answer 1

From your ZonedDateTime you need to specify in which other zone you want your OffsetDateTime , precise the zone and them use .toOffsetDateTime() :

ZonedDateTime z = ZonedDateTime.parse("2018-10-30T18:04:58.874Z");
System.out.println(z); //2018-10-30T18:04:58.874Z

OffsetDateTime o = z.withZoneSameInstant(ZoneId.of("UTC-5")).toOffsetDateTime();
System.out.println(o); //2018-10-30T13:04:58.874-05:00

Answer 2

这会将时区从当前/现在转移：

someOffsetDateTime.withOffsetSameInstant(OffsetDateTime.now().getOffset())

Answer 3

I think the correct way to do it is as follows:

ZonedDateTime date = ZonedDateTime.parse("2018-10-30T18:04:58.874Z");
ZoneOffset offset = ZoneId.systemDefault().getRules().getOffset(date.toInstant());
ZonedDateTime dateInMyZone = date.withZoneSameInstant(offset)

getting it from now() will give you a possibly wrong result casue the offset can change during the year due to DST