Some save the zone information as well, but some such as Postgres discard the zone info after using it to adjust into UTC. If you care about remembering that original zone, you may need to store its name in a separate column alongside. Another reason to use Local… types is for future appointments. Politicians enjoy frequently changing their time zone s of their jurisdiction.
The like to change the dates of their DST cutovers. They like to drop their adoption of DST. They like to redefine their time zones, changing the boundaries. They like to redefine their offset-from-UTC sometimes by amounts like 15 minutes. And they rarely give advance notice, making such changes with as little as a month or two of warning. So to make medical check-up appointment for next year or in six months, the time zone definition cannot be predicted.
But do not rely on those too far out in time when politicians may ruin their meaning by changing the zone s. Tip: These frequent changes to DST and time zones means you must keep your time zone tzdata data base up to date. All three should be frequently updated. Sometimes the zones change faster than the planned update cycles of those products such as Turkey last year deciding to stay on DST with only several weeks notice.
So you may occasionally need to manually update those tzdata files. Oracle provides a tool for updating the tzdata of their Java implementations. The general best practice in handling exact moments is to track them in UTC.
Apply a time zone only where necessary such as in presentation to a user where they expect to see values in their own parochial time zone. In java. In UTC with a resolution of nanoseconds.
By the way, drivers that comply with JDBC 4. Avoid the old legacy data types such as java. Date and java. Timestamp whenever possible. They are poorly designed, confusing, and flawed. If you want a date-only value without time-of-day and without time zone, use java. This class supplants java. As for specific databases, be aware that the SQL standard barely touches on the topic of date-time types and their handling.
Furthermore, the various databases vary widely, and I really mean widely , in their support of date-time features.
Some have virtually no support. Some mix SQL standard types with proprietary types that either predate the standard types or are intended as alternatives to the standard types. Be sure to study the documentation and practice, practice, practice.
If using Instant, will there be a possibility to store only the date part, without time? You need to remove Temporal TemporalType. Part of the new Date API they split the types of dates up.
The correct class that includes timezones is ZonedDateTime. Mikhail Kholodkov 6, 6 6 gold badges 32 32 silver badges 55 55 bronze badges. Why not use OffsetDateTime? But still the same moment in the timeline. Understand that all of these four are representations of a moment on the timeline in UTC: Modern java. The canonical reference for building a production grade API with Spring. If you have a few years of experience in the Java ecosystem, and you're interested in sharing that experience with the community and getting paid for your work of course , have a look at the "Write for Us" page.
The JPA 2. Before we start, we need to include the JPA 2. Here, n is the fractional seconds precision and is between 0 and 9 digits. Date, and java.
Timestamp, respectively, or to java. Date and java.
While the java. None of these types have support for the timezone or the offset. To deal with those pieces of information, we traditionally had to store the UTC time.