About hunt-time
hunt-time is a time library and similar to Joda-time and Java.time api.
Features
- LocalDate - date without time
- LocalTime - time without date
- Instant - an instantaneous point on the time-line
- DateTime - full date and time with time-zone
- DateTimeZone - a better time-zone
- Duration and Period - amounts of time
- Interval - the time between two instants
- A comprehensive and flexible formatter-parser
Working With Zones and Offsets: ZondedDateTime and OffsetDateTime
Thus far, we’ve shown how the new date APIs have made a few things a little easier. What really makes a difference, however, is the ability to easily use date and time in a timezone context. Hunt.time provides us with ZonedDateTime and OffsetDateTime, the first one being a LocalDateTime with information for a specific Zone (e.g. Europe/Paris), the second one being a LocalDateTime with an offset. What’s the difference? OffsetDateTime uses a fixed time difference between UTC/Greenwich and the date that is specified, whilst ZonedDateTime specifies the zone in which the time is represented, and will take daylight saving time into account.
Converting to either of these types is very easy:
OffsetDateTime offsetDateTime = LocalDateTime.parse("2018-02-14T06:30").atOffset(ZoneOffset.ofHours(2));
// Uses DateTimeFormatter.ISO_OFFSET_DATE_TIME for which the default format is
// ISO_LOCAL_DATE_TIME followed by the offset ("+HH:mm:ss").
OffsetDateTime offsetDateTime = OffsetDateTime.parse("2018-02-14T06:30+06:00");
ZonedDateTime zonedDateTime = LocalDateTime.parse("2018-02-14T06:30").atZone(ZoneId.of("Europe/Paris"));
// Uses DateTimeFormatter.ISO_ZONED_DATE_TIME for which the default format is
// ISO_OFFSET_DATE_TIME followed by the the ZoneId in square brackets.
ZonedDateTime zonedDateTime = ZonedDateTime.parse("2018-02-14T06:30+08:00[Asia/Macau]");
// note that the offset does not matter in this case.
// The following example will also return an offset of +08:00
ZonedDateTime zonedDateTime = ZonedDateTime.parse("2018-02-14T06:30+06:00[Asia/Macau]");
When switching between them, you have to keep in mind that converting from a ZonedDateTime to OffsetDateTimewill take daylight saving time into account, while converting in the other direction, from OffsetDateTime to ZonedDateTime, means you will not have information about the region of the zone, nor will there be any rules applied for daylight saving time. That is because an offset does not define any time zone rules, nor is it bound to a specific region.
ZonedDateTime winter = LocalDateTime.parse("2018-01-14T06:30").atZone(ZoneId.of("Europe/Paris"));
ZonedDateTime summer = LocalDateTime.parse("2018-08-14T06:30").atZone(ZoneId.of("Europe/Paris"));
// offset will be +01:00
OffsetDateTime offsetDateTime = winter.toOffsetDateTime();
// offset will be +02:00
OffsetDateTime offsetDateTime = summer.toOffsetDateTime();
OffsetDateTime offsetDateTime = zonedDateTime.toOffsetDateTime();
OffsetDateTime offsetDateTime = LocalDateTime.parse("2018-02-14T06:30").atOffset(ZoneOffset.ofHours(5));
ZonedDateTime zonedDateTime = offsetDateTime.toZonedDateTime();
TODO
- [ ] Improve formatter
- [ ] More unit tests