CODEWITHSUNDEEP
javajdbctimestampzoneddatetime
Skywarp
Skywarp

Reputation: 1059

How do you save a UTC Timestamp?

How do you convert a ZonedDateTime to an SQL Timestamp and retain the Timezone info? I am trying to take a UTC zoned time, convert it to a Timestamp, and then convert it back, but when I convert to Timestamp, it loses the time zone info and the Timestamp is created using my local time zone:

public static void main(String[] args) {

    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("hh:mm a");

    ZonedDateTime zdtUTC = ZonedDateTime.now(ZoneId.of("UTC"));

    ZonedDateTime zdtNY = zdtUTC.withZoneSameInstant(ZoneId.of("America/New_York"));
    ZonedDateTime zdtAZ = zdtUTC.withZoneSameInstant(ZoneId.of("America/Phoenix"));
    ZonedDateTime zdtUK = zdtUTC.withZoneSameInstant(ZoneId.of("Europe/London"));

    System.out.println(formatter.format(zdtUTC) + " in UTC zone");
    System.out.println(formatter.format(zdtNY) + " in New York, NY");
    System.out.println(formatter.format(zdtAZ) + " in Phoenix, AZ");
    System.out.println(formatter.format(zdtUK) + " in London, UK");

    Timestamp timestamp = Timestamp.from(zdtUTC.toInstant());

    LocalDateTime converted = timestamp.toLocalDateTime();
    ZonedDateTime convertedZdt = ZonedDateTime.of(converted, ZoneId.of("UTC"));

    System.out.println(timestamp);

    System.out.println(formatter.format(convertedZdt) + " in UTC zone");

}

06:33 PM in UTC zone
02:33 PM in New York, NY
11:33 AM in Phoenix, AZ
07:33 PM in London, UK
2017-05-07 14:33:06.745
02:33 PM in UTC zone

What do I need to do to ensure that the Timestamp records using the correct time zone info?

Upvotes: 0

Views: 1285

Answers (1)

Gord Thompson
Gord Thompson

Reputation: 123809

when I convert to Timestamp, it loses the time zone info and the Timestamp is created using my local time zone

No. When you convert the original ZonedDateTime zdtUTC to a java.sql.Timestamp you get the same moment in time. This can be verified by formatting and displaying the timestamp value directly:

Timestamp timestamp = Timestamp.from(zdtUTC.toInstant());  // as before
// verify the timestamp value directly
java.text.SimpleDateFormat sdfUTC = new java.text.SimpleDateFormat("hh:mm a z");
sdfUTC.setCalendar(java.util.Calendar.getInstance(java.util.TimeZone.getTimeZone("UTC")));
System.out.printf("timestamp is %s%n", sdfUTC.format(timestamp));

That will print the same value as the first line of your output:

08:30 PM in UTC zone
...
timestamp is 08:30 PM UTC

It's the subsequent conversion to LocalDateTime and then back to ZonedDateTime that "loses" the timezone information.

Upvotes: 2

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