Parse ISO-8601 Datetime

Question

It seems the proper form of timestamp to parse ISO-8601 in Java looks like:

"2020-02-03T23:40:17+00:00";

However mine looks like:

"2020-02-03T23:40:17+0000";

How can I parse this properly?

import java.time.OffsetDateTime;
import java.time.format.DateTimeFormatter;

 public class TestTime {
        public static void main(String[] args) {

            String ts = "2020-02-03T23:40:17+0000";
            DateTimeFormatter timeFormatter = DateTimeFormatter.ISO_DATE_TIME;
            OffsetDateTime offsetDateTime = OffsetDateTime.parse(ts, timeFormatter);
            long timestamp = offsetDateTime.toEpochSecond() * 1000;

        }
    }

Maybe change your `DateTimeFormatter` to the format that you want? — Scary Wombat, Feb 03 '20 at 23:56
Does this answer your question? [How to parse a date?](https://stackoverflow.com/questions/999172/how-to-parse-a-date) — itwasntme, Feb 04 '20 at 00:09
@itwasntme This doesn't work `new SimpleDateFormat("yyyy-MM-ddTHH:mm:ssXXXX")` — BAR, Feb 04 '20 at 00:15
`OffsetDateTime.parse("2020-02-03T23:40:17+0000", DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ssX"))` ==> `2020-02-03T23:40:17Z` — ernest_k, Feb 04 '20 at 00:23
Similar to above comment try something like `DateTimeFormatter timeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ssXXXX");` — itwasntme, Feb 04 '20 at 00:25
Both `±hh:mm` and `±hhmm` are valid ISO 8601 time zone formats. Q: Are you saying that only one format works with Java8 time? Q: What error(s) are you seeing? — FoggyDay, Feb 04 '20 at 01:09
@FoggyDay While both offset formats are valid in itself, `2020-02-03T23:40:17+0000` is not as it mixes what ISO 8601 calls basic and extended format. — Christian S., Feb 04 '20 at 01:32
@Christian S. - and RFC 3399 *requires* `±hh:mm` (as, apparently, does the default Java8 time parser). Hopefully BAR has the luxury of slapping whoever gave him that `±hhmm` format. I'm curious if `DateTimeFormatter.ofPattern()` mitigates the problem. I'm also curious why you suggested `ssZZZ`. It's not clear from your explanation, or from my understanding of ISO 8601. Is it a "Java8 DateTimeFormatter" thing? — FoggyDay, Feb 04 '20 at 02:01
That doesn't have to do with ISO 8601, it's just the offset pattern that matches OP's format (see [Offset Z](https://docs.oracle.com/en/java/javase/13/docs/api/java.base/java/time/format/DateTimeFormatter.html)). — Christian S., Feb 04 '20 at 09:18

score 1 · Answer 1 · answered Feb 04 '20 at 01:04

You could pass a pattern to the DateTimeFormatter:

String ts = "2020-02-03T23:40:17+0000";
DateTimeFormatter timeFormatter = DateTimeFormatter.ofPattern("uuuu-MM-dd'T'HH:mm:ssZZZ");
OffsetDateTime offsetDateTime = OffsetDateTime.parse(ts, timeFormatter);

Note that the correct pattern for the offset is ZZZ instead of X or XXXX, which becomes obvious when, for example, formatting the parsed date-time back to a string:

DateTimeFormatter timeFormatter = DateTimeFormatter.ofPattern("uuuu-MM-dd'T'HH:mm:ssX");
OffsetDateTime offsetDateTime = OffsetDateTime.parse(ts, timeFormatter);
System.out.println(offsetDateTime.format(timeFormatter));

2020-02-03T23:40:17Z

While when using ZZZ, it will format like 2020-02-03T23:40:17+0000. See the documentation for DateTimeFormatter.

Parse ISO-8601 Datetime

1 Answers1