Closed. This question needs details or clarity. It is not currently accepting answers.
Want to improve this question? Add details and clarify the problem by editing this post.
Closed 1 year ago.
Improve this question
how to convert ISO_LOCAL_DATE to date time format : yyyy-MM-dd'T'HH:mm:ss.SSSZ in java
Ex: given date: 2016-01-25 to 2016-01-25T00:00:00.000+0100
I am assuming that have got a string, for example 2016-01-25, and that you want a string containing the start of the day in the JVM’s default time zone (it wasn’t clear from the question). I first define a formatter for the format that you want (it’s ISO 8601):
private static DateTimeFormatter formatter
= DateTimeFormatter.ofPattern("uuuu-MM-dd'T'HH:mm:ss.SSSxx");
Now your conversion goes:
String isoLocalDateString = "2016-01-25";
LocalDate date = LocalDate.parse(isoLocalDateString);
ZonedDateTime dateTime = date.atStartOfDay(ZoneId.systemDefault());
String dateTimeString = dateTime.format(formatter);
System.out.println(dateTimeString);
When running in my time zone, Europe/Copenhagen, output from this example code is what you asked for:
2016-01-25T00:00:00.000+0100
In rare cases where summer time (DST) begins at the first moment of the day, the time of day will not be 00:00:00.000.
For parsing with ISO_LOCAL_DATE we don’t need to specify the formatter since this formatter is the default for LocalDate.parse().
All of this said, you should not normally want to convert a date from one string format to another string format. Inside your program keep dates as LocalDate objects. When you get string input, parse into a LocalDate. Only when you need to give string output, for example in data exchange with another system, format into a string in the required format.
Link: Wikipedia article: ISO 8601
There are various methods on LocalDate for this, including:
LocalDate::toDateTimeAtCurrentTime()
LocalDate::toDateTimeAtStartOfDay()
LocalDate::toDateTime( LocalTime )
LocalDate::toDateTime( LocalTime , DateTimeZone )
It is as simple as LocalDateTime localDateTime = yourLocalDate.atStartOfDay()
Update
Adding timestamp is as simple as:
ZoneId zoneId = ZoneId.of("America/New_York");
ZonedDateTime = zdt = localDateTime.atZone(zoneId);
Can be put together as
ZonedDateTime zdt = yourLocalDate.atStartOfDay().atZone(ZoneId.of("America/New_York"));
Related
Closed. This question needs details or clarity. It is not currently accepting answers.
Want to improve this question? Add details and clarify the problem by editing this post.
Closed 7 months ago.
Improve this question
Does anyone know how to grab or create the cdate value from Date? I haven't been able to figure out how to do so and I don't know how to necessarily get it. In the Date class it is there as
private transient BaseCalendar.Date cdate; I don't see an option to grabt the field from the Date object itself.
I am setting this date using request.setGatewayEndTime(Calendar.getInstance().getTime());
where the calendar is from the java.util.Calendar import
debug pic
As commented, trying to access internally defined fields that were intentionally hidden from outside calling programmers would be unwise.
As commented, you seem to have an XY Problem. I'll take a stab at what you might need.
You are using terrible date-time classes that were years ago supplanted by the modern java.time classes defined in JSR 310. Never use Calendar, Date, etc.
You claim to have a call to a method requiring a java.util.Date object that represents the current moment as seen in UTC, that is, with an offset of zero hours-minutes-seconds. To capture the current moment, use Instant class.
Instant now = Instant.now() ; // Current moment as seen with an offset of zero.
I suggest you educate the author of that called method about how Date has been replaced by Instant.
Until they update their API, you can easily convert between legacy and modern classes by calling conversion methods added to the old classes.
java.util.Date d = Date.from( now ) ;
request.setGatewayEndTime( d );
As for the BaseCalendar.Date field, if your goal is to get a string in ISO 8601 format similar to the string you show in your screenshot which is nearly in standard format but omits the COLON from between the hours and minutes of the offset, then simply call Instant#toSting. The java.time classes use ISO 8601 format by default when parsing/generating strings.
String output = now.toString() ; // Generate text in standard ISO 8601 format.
Your screenshot uses another offset other than zero. If you wish to see a moment with the offset of a particular time zone, apply a ZoneID object to produce a ZonedDateTime object.
ZoneId z = ZoneId.of( "America/La_Paz" ) ;
ZonedDateTime zdt = now.atZone( z ) ;
Produce text in standard ISO 8601 format that has been wisely extended to include the name of the time zone in square brackets.
String output = zdt.toString() ;
Closed. This question needs details or clarity. It is not currently accepting answers.
Want to improve this question? Add details and clarify the problem by editing this post.
Closed 8 months ago.
Improve this question
I have a date say 2022-07-10 as date (YYY/MM/dd) and time as 00:15
ie. 202207**10*****0015***
after subtracting 30 mins from above the result must be
2022-07-09 and time as 23:45
ie. 202207**09***2345***
other scenarios:
202207100030 -->202207100000
202207100010 -->202207092340
202207100035 -->202207100005
Could you please help me out with this.
What you want doesn't make sense. 2022-07-10 00:15 minus 30 minutes? That's not 2022-07-09 23:45. Not neccessarily, anyway. Maybe a timezone shift means it's 2022-07-10 00:45 (but, before the timezone change). Or it's 2022-07-09 22:45. Or perhaps it's 2022-07-01 23:45 - it's been a good long while but a locale can skip a day (last time: When one of the islands in the pacific decided to hop across the date line), or even half a month (last time: Russian revolution. It's still in the 1900s).
You can't 'do' date-diff math on Local date/time concepts; a time zone is required.
Once you've established one this is trivial:
First, parse whatever you have into a LocalDate, LocalDateTime, OffsetDateTime, Instant, or ZonedDateTime object. These are all fundamentally different concepts - a key part of doing any time-based anything is figuring out what concept you're dealing with. For example, you seem to believe you're dealing with local date/times (no timezone), and yet also with a concept that can 'do' date diff math (which is mutually exclusive, hence, some more analysis of the situation is required).
Then, transform what you have into the date/time concept you need to do the operation.
Do the operation.
Transform some more if needed.
format it back to a string if you want.
If you try to shortcut and skip steps, it'll work, until it doesn't. Because date/time is just that hard.
For example:
DateTimeFormatter dtf = DateTimeFormatter.ofPattern("uuuuMM**dd*****HHmm***");
LocalDateTime ldt = LocalDateTime.parse("202207**10*****0015***", dtf);
This is a good start; you now have an LDT object with the right year, month, day, minute, and hour.
Let's localize it somewhere and do the math:
ZonedDateTime zdt = ldt.atZone(ZoneId.of("Europe/Amsterdam"));
zdt = zdt.minusMinutes(30);
System.out.println(zdt.format(dtf));
Prints 202207**09*****2345***; I assume that's what you want.
You need to use LocalDateTime.minus method:
DateTimeFormatter DATEFORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm");
LocalDateTime d = LocalDateTime.parse("2022-07-10 00:10", DATEFORMATTER);
d.atZone(ZoneId.systemDefault());
LocalDateTime d2 = d.minus(Duration.ofMinutes(30));
LocalDateTime d3 = d.minus(30, ChronoUnit.MINUTES);
System.out.println(d2); //2022-07-09T23:40
System.out.println(d3); //2022-07-09T23:40
Closed. This question needs details or clarity. It is not currently accepting answers.
Want to improve this question? Add details and clarify the problem by editing this post.
Closed 2 years ago.
Improve this question
I work with the date in my API on Java. I want to get today's date and time, write it to a class and then to a csv file (I use a csv file as a data store). Then, to implement the function of getting a report on records for today, to get it and to compare it with today's date (exactly the date, without time). What is the best way to do this? Right now I'm storing this in Timestamp, but it doesn't seem to be correct and should I use String? Then I need two parsers? To translate from a string to a date and time and from that to just a DATE? Which library is better to use for this?
I wrote a translation from a string to a timestamp, is this correct?
default Timestamp StringToTimestamp(String date) {
SimpleDateFormat dateFormat = new SimpleDateFormat("dd-MM-YYYY");
Date parsedDate = null;
try {
parsedDate = dateFormat.parse(date);
} catch (ParseException e) {
e.printStackTrace();
log.error("Error in date parsing");
}
return new Timestamp(parsedDate.getTime());
}
UPD
I changed my code for the java.time library, but it seems I did something wrong
default LocalDate StringToTimestamp(String date) {
DateTimeFormatter dtf = DateTimeFormatter.ofPattern('yyyy-mm-dd');
LocalDate date = LocalDate.parse(date, dtf);
return date;
}
UPD I edited the code according to the answer #OleV.V. It works really cool
java.time
I recommend that you use java.time, the modern Java date and time API, for your date and time work. I suggest writing the current date and time with offset from UTC to the CSV file.
OffsetDateTime dateTime = OffsetDateTime.now(ZoneId.systemDefault());
String stringForCsvFile = dateTime.toString();
System.out.println(stringForCsvFile);
Output when running in my time zone just now:
2020-12-26T11:02:07.368973+01:00
The string is in ISO 8601 format, which should be the best to avoid surprises for anyone reading it. The classes of java.time generally print ISO 8601 format from their toString methods.
Often you will value consistency higher than knowing which UTC offset was used when writing the file. If so, write the time in UTC to the file:
Instant now = Instant.now();
String stringForCsvFile = now.toString();
2020-12-26T10:02:07.373439Z
No matter which way you used above, after reading the timestamp from the file, convert like this:
ZoneId zone = ZoneId.systemDefault();
String stringFromCsvFile = "2020-12-26T11:02:07.368973+01:00";
ZonedDateTime dateTime = OffsetDateTime.parse(stringFromCsvFile)
.atZoneSameInstant(zone);
LocalDate dateFromCsv = dateTime.toLocalDate();
LocalDate today = LocalDate.now(zone);
System.out.println("Same day? " + dateFromCsv.isEqual(today));
Same day? true
I have made sure that both dates I compare are in the time zone of the JVM where the program is running. Please consider whether there’s a specific time zone you want, and if so, set zone to something like ZoneId.of("Asia/Baku"). It matters: it is never the same date in all time zones.
If you want to know whether the date is earlier or later, use the isBefore or isAfter method of LocalDate.
Was your code correct?
IMHO the worst problem with your code is using the old and poorly designed date-time classes: SimpleDateFormat, Date and Timestamp. SimpleDateFormat is a notorious troublemaker of a class. Date had severe design flaws in Java 1.0, therefore most constructors and methods were deprecated already in Java 1.1. Timestamp was never meant for other purposes than transferring high-precision timestamps to and from SQL databases (which we also don’t use it for anymore). And it’s a true hack on top of the already poorly designed Date class. I furthermore see nothing that you will want to use the high precision of Timestamp for, so using it here seems pointless.
There is a bug in your code: You are using upper case YYYY in your format pattern. This is for week year and only useful with a week number. I tried giving 24-06-2021 to your method. It returned 2021-01-04 00:00:00.0. It’s 5 months 20 days off because of the mentioned error. Apparently SimpleDateFormat defaulted to the start of week 1 in the week year and ignored the month and day of month.
As an aside, had you tried parsing with the same format pattern string with java.time, it would at least have told you that this was wrong.
Links
Oracle tutorial: Date Time explaining how to use java.time.
Wikipedia article: ISO 8601
Related question: java parsing string to date
Closed. This question needs debugging details. It is not currently accepting answers.
Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 2 years ago.
Improve this question
I have a String value as follows
2018-12-05 18:11:27.187
How can I can convert it into a LocalDate object based on that format "MM/dd/YYYY HH:mm:ss" ?
a LocalDate object is what it is. It has no format; it is an object with methods; these methods make it do stuff.
You can for example ask a localdate to return the year of the date it represents. You can also ask it to render itself as a string using some format. That string is then not a LocalDate (it is a String).
Furthermore, a localdate represents a date. Hence the name. 'hour' is not part of a date. YYYY is the pattern for week based year. You don't want that.
So, fixing your misconceptions, we end up with:
DateTimeFormatter inFormat = DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss.SSS");
DateTimeFormatter outFormat = DateTimeFormatter.ofPattern("MM/dd/uuuu HH:mm:ss");
LocalDateTime when = LocalDateTime.parse("2018-12-05 18:11:27.187", inFormat);
System.out.println(outFormat.format(when));
Firstly you need to define the pattern of your current Date and Time input
Parse the current Date and Time to LocalDateTime class
Print the value to the new Date and Time format you want.
LocalDateTime date = LocalDateTime.parse("2018-12-05 18:11:27.187", DateTimeFormatter.ofPattern("uuuu-MM-dd HH:mm:ss.SSS"));
System.out.println(date.format(DateTimeFormatter.ofPattern("MM/dd/uuuu HH:mm:ss")));
Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 3 years ago.
Improve this question
I have a string date. Eg: "2020-02-21 16:36:30.072" and I want to convert it to Date "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'". (i.e. 2020-02-21T16:36:30.072+05:30)
How? Could you please help me?
You need to start by converting the String into a more "malleable" format - something which can represent the date/time in a way through which you can generate different formats based on your need
Since it's 2020, you should start with the java.time.* API.
String input = "2020-02-21 16:36:30.072";
DateTimeFormatter inputFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss.SSS");
LocalDateTime ldt = LocalDateTime.parse(input, inputFormatter);
Ok, now, part of your requirement is to have the time zone, so you'll need to convert the LocalDateTime to a ZonedDateTime, you could, technically, do this in a single step, but it's a good demonstration
ZonedDateTime zdt = ldt.atZone(ZoneId.systemDefault());
DateTimeFormatter outputFormatter = DateTimeFormatter.ISO_OFFSET_DATE_TIME;
String output = outputFormatter.format(zdt);
System.out.println(input);
System.out.println(output);
This will output
2020-02-21 16:36:30.072
2020-02-21T16:36:30.072+11:00
I live in Australia, so my time zone is +10 (and +1 for daylight savings). You can specify a specific time zone if you wish, this is just for demonstration (and I couldn't be bothered trying to figure out 530+ time zone ;))
tl;dr
Here is a one-liner.
LocalDateTime
.parse(
"2020-02-21 16:36:30.072".replace( " " , "T" )
) // Returns a `LocalDateTime` object. *Not* a moment, *not* a point on the timeline. Just a date and a time-of-day, nothing more. Lacks context of a time zone or offset-from-UTC.
.atZone( // Lending context to our `LocalDateTime` object to determine a moment by assigning a time zone.
ZoneId.of( "Asia/Kolkata" ) // Currently using an offset of five and a half hours ahead of UTC.
) // Returns a `ZonedDateTime` object.
.format( // Generates text representing the value of the `ZonedDateTime` object.
DateTimeFormatter.ISO_OFFSET_DATE_TIME // Pre-defined formatter. No need to specify your own formatting pattern. Your desired format complies with the ISO 8601 standard.
) // Returns a `String`.
See this code run live at IdeOne.com.
2020-02-21T16:36:30.072+05:30
Details
The Answer by MadProgrammer is correct and nicely detailed. I will take some shortcuts, and address specifically your desired offset of +05:30.
We can parse your input as a LocalDateTime by merely replacing the SPACE character in the middle with an uppercase T.
String input = "2020-02-21 16:36:30.072".replace( " " , "T" ) ;
LocalDateTime ldt = LocalDateTime.parse( input ) ;
A LocalDateTime does not represent a moment, is not a point on the timeline. It lacks the context of a time zone or offset-from-UTC.
Your desired offset of +05:30 is currently used in only two time zones:
Asia/Colombo (Sri Lanka)
Asia/Kolkata (India)
Pick which one is yours.
ZoneId z = ZoneId.of( "Asia/Kolkata" ) ;
Apply to your LocalDateTime to determine a moment, resulting in a ZonedDateTime.
ZonedDateTime zdt = ldt.atZone( z ) ;
Generate a String in standard ISO 8601 format extended wisely to append the name of the zone in square brackets.
String output = zdt.toString() ;
If you really want the offset only without the time zone, keep in mind that readers of your data won't know for sure if you meant Sri Lanka time or India time. If you insist, use the predefined DateTimeFormatter object as shown in the other Answer.
import java.util.Date;
public class Test {
public static void main(String[] args) {
String s0="2020-02-21 16:36:30.072";
Date date=new Date();
String sd=s0.split(" ")[0];
date.setDate(Integer.parseInt(sd.split("-")[2]));
date.setMonth(Integer.parseInt(sd.split("-")[1])-1);
date.setYear(Integer.parseInt(sd.split("-")[0])-1900);
String st=s0.split(" ")[1];
date.setSeconds((int) Double.parseDouble(st.split(":")[2]));
date.setMinutes(Integer.parseInt(st.split(":")[1]));
date.setHours(Integer.parseInt(st.split(":")[0]));
System.out.print(date);
}
}