I have a UTC date-time like this (a String): 2022-11-22T17:15:00
And a ZoneID like this: "America/Tijuana"
Using java.time API, I want to get the actual datetime for that zone, which is: 2022-11-22T09:15:00
(the time is 09:15 instead of 17:15)
2022-11-22T17:15
2022-11-22T17:15-08:00[America/Tijuana]
None of the above gives me what I'm looking for.
This is my code:
ZoneId zonaID = ZoneId.of('America/Tijuana');
CharSequence dateUTC = "2022-11-22T17:15:00";
LocalDateTime dateTimeL = LocalDateTime.parse(dateUTC);
ZonedDateTime myZDT = ZonedDateTime.now();
ZonedDateTime myZDTFinal = myZDT.of(dateTimeL, zonaID);
System.out.println("using toLocalDateTime: " + myZDTFinal.toLocalDateTime());
System.out.println("using toString: " + myZDTFinal.toString());
I know that this might be a duplicated question but there's so many questions about date-times and I just haven't been able to figure out this.
Any help will be really appreciated.
You have to convert your date to UTC, then convert the convert this zone to your expected zone using withZoneSameInstant
like this:
ZonedDateTime toUTCZone = ZonedDateTime.of(dateTimeL, ZoneOffset.UTC);
ZonedDateTime myZDTFinal = toUTCZone.withZoneSameInstant(zonaID);
Output
2022-11-22T09:15-08:00[America/Tijuana]
There can be many ways to achieve the result. A simple approach would be
LocalDateTime
.OffsetDateTime
at UTC using LocalDateTime#atOffset
.OffsetDateTime#atZoneSameInstant
to convert the resulting OffsetDateTime
into a ZonedDateTime
at ZoneId.of("America/Tijuana")
.LocalDateTime
out of the resulting ZonedDateTime
by using ZonedDateTime#toLocalDateTime
.LocalDateTime
into the desired string.LocalDateTime
.parse("2022-11-22T17:15:00") // Parse the given date-time string into LocalDateTime
.atOffset(ZoneOffset.UTC) // Convert it into a ZonedDateTime at UTC
.atZoneSameInstant(ZoneId.of("America/Tijuana")) // Convert the result into a ZonedDateTime at another time-zome
.toLocalDateTime() // Get the LocalDateTime out of the ZonedDateTime
.format(DateTimeFormatter.ofPattern("uuuu-MM-dd'T'HH:mm:ss", Locale.ENGLISH))); // If required
Demo :
import java.time.LocalDateTime;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;
import java.util.Locale;
public class Main {
public static void main(String[] args) {
LocalDateTime ldtInTijuana = LocalDateTime.parse("2022-11-22T17:15:00")
.atOffset(ZoneOffset.UTC)
.atZoneSameInstant(ZoneId.of("America/Tijuana"))
.toLocalDateTime();
System.out.println(ldtInTijuana);
// Custom format
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("uuuu-MM-dd'T'HH:mm:ss", Locale.ENGLISH);
String formatted = ldtInTijuana.format(formatter);
System.out.println(formatted);
}
}
Output :
2022-11-22T09:15
2022-11-22T09:15:00
Note that LocalDateTime#toString
removes second and fraction-of-second values if they are zero. Suppose you want to keep them ( as you have posted in your question ), you can use a DateTimeFormatter
as shown above.
Alternatively, you can append Z
at the end of your ISO 8601 formatted date-time string to enable Instant
to parse it and then convert the Instant
into a ZonedDateTime
corresponding to the ZoneId.of("America/Tijuana")
by using Instant#atZone
. The symbol, Z
refers to UTC in a date-time string.
The rest of the steps will remain the same.
Demo :
public class Main {
public static void main(String[] args) {
String text = "2022-11-22T17:15:00";
text = text + "Z"; // Z refers to UTC
Instant instant = Instant.parse(text);
LocalDateTime ldt = instant.atZone(ZoneId.of("America/Tijuana")).toLocalDateTime();
System.out.println(ldt);
}
}
Output :
2022-11-22T09:15
Learn more about the modern Date-Time API from Trail: Date Time .
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.