The accepted answer give very completed explanation, perhaps below code example can provide you short and clear picture:
Instant instant = Instant.now();Clock clock = Clock.fixed(instant, ZoneId.of("America/New_York"));OffsetDateTime offsetDateTime = OffsetDateTime.now(clock);ZonedDateTime zonedDateTime = ZonedDateTime.now(clock);System.out.println(offsetDateTime); // 2019-01-03T19:10:16.806-05:00System.out.println(zonedDateTime); // 2019-01-03T19:10:16.806-05:00[America/New_York]System.out.println();OffsetDateTime offsetPlusSixMonths = offsetDateTime.plusMonths(6);ZonedDateTime zonedDateTimePlusSixMonths = zonedDateTime.plusMonths(6);System.out.println(offsetPlusSixMonths); // 2019-07-03T19:10:16.806-05:00System.out.println(zonedDateTimePlusSixMonths); // 2019-07-03T19:10:16.806-04:00[America/New_York]System.out.println(zonedDateTimePlusSixMonths.toEpochSecond() - offsetPlusSixMonths.toEpochSecond()); // -3600System.out.println();System.out.println(zonedDateTimePlusSixMonths.toLocalDateTime()); // 2019-07-03T19:10:16.806System.out.println(offsetPlusSixMonths.toLocalDateTime()); // 2019-07-03T19:10:16.806In short, use ZonedDateTime only if you want to factor in Daylight saving, typically there will be one hour difference, as you can see the example above, the offset of ZonedDateTime change from -5:00 to -04:00, in most case, your business logic might end up with bug.
(code copy from https://www.youtube.com/watch?v=nEQhx9hGutQ)