I am baffled why this doesn't work. No matter what I change the day to, it prints out the same thing. What is going on here?
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/YYYY");
String s = "11/22/2000";
Date d = sdf.parse(s);
System.out.println(d.toString());
Output: Sun Dec 26 00:00:00 CST 1999
You're using YYYY which is the week-year instead of the "normal" year. That's usually only used with day-of-week and week-of-year specifiers.
The exact behaviour here would be hard to explain - feasible, but not terribly helpful. Basically the solution is "don't do that". You want a format string of MM/dd/yyyy instead - note the case of the yyyy.
(As a side note, if you can possibly use java.time.* from Java 8 or Joda Time, you'll have a lot better time in Java with date/time issues. It wouldn't affect this particular issue, but it's generally a good idea...)
Use
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy")
instead of
SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/YYYY");
Related
This question already has answers here:
ParseException when parsing 3 character abbreviated month using SimpleDateFormat
(5 answers)
Closed 4 years ago.
i have a SimpleDateFormat format = new SimpleDateFormat("d M y H:m"); and i try to parse the String "8 Jan 2019 16:47" with it, but i get a ParseException. Did i create it the wrong way?
According to docs.oracle.com the M should recognize 3-letter-months.
Can anyone help me?
The official documentation: (https://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html)
You probably missed out this little note here:
Month: If the number of pattern letters is 3 or more, the month is interpreted as text; otherwise, it is interpreted as a number.
Based on your example input, the following works:
SimpleDateFormat format = new SimpleDateFormat("dd MMM yyyy HH:mm");
java.time
DateTimeFormatter formatter = DateTimeFormatter.ofPattern("d MMM y H:mm", Locale.ENGLISH);
String stringToParse = "8 Jan 2019 16:47";
LocalDateTime dateTime = LocalDateTime.parse(stringToParse, formatter);
System.out.println(dateTime);
The output from this snippet is:
2019-01-08T16:47
What went wrong in your code?
SimpleDateFormat and Date are poorly designed and long outdated, the former in particular notoriously troublesome. I recommend you don’t use them in 2019.
As others have said you need three M for month abbreviation (no matter if you are using the outdated SimpleDateFormat or the modern DateTimeFormatter). One M will match a month number in 1 or 2 digits, for example 1 for January.
You should also specify a locale for your formatter. I took Jan to be English so specified Locale.ENGLISH. If you don’t specify locale, the JVM’s default locale will be used, which may work well on some JVMs and suddenly break some day when the default locale has been changed or you are trying to run your program on a different computer.
Link
Oracle tutorial: Date Time explaining how to use java.time.
I ma getting exeception while parsing the date.
following is the code:
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-DD");
Date d = format.parse("2014/02/20");
System.out.println(d);
Not only have you got the slashes/dashes wrong, you're also using DD (day of year) instead of dd (day of month). You want:
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
As always, read the documentation to find out exactly what pattern symbols mean - and if you find it's behaving oddly, check the pattern against the data very carefully.
I would also recommend:
Using Joda Time (pre-Java-8) or java.time (Java 8) if you possibly can; the java.util.Date/Calendar API is horrible
Specifying the locale explicitly
Specifying the time zone explicitly
Currently you're using the default time zone and locale. While the locale may not matter in this case (unless it's used to pick the calendar system; I can't remember offhand) I think it's clearer to explicitly specify it. The time zone definitely matters; if you only ever want to treat this as a date (no time) it's probably worth specifying UTC - that way it's easy to interoperate with anything else, and you get day boundaries in obvious places in the underlying millisecond representation.
Your dateformat doesn't match your string.
Date d = format.parse("2014-02-20");
or
SimpleDateFormat format = new SimpleDateFormat("yyyy/MM/dd");
I have a varaibles:
Date date;
Time time;
and methods:
MyDateMethod(Date date){
//do stuff
}
MyTimeMethod(Time time){
//do stuff
}
I tried using MyDateMethod() with the following call:
MyDateMethod(1995-03-7);
I get an error saying I've supplied it with type int when it expected type Time.
I also tried using MyTimeMethod() with the following call:
MyTimeMethod(03:04:55);
I get an error saying Type mismatch: Cannot convert type int to boolean.
What is the format to put in a variable of these different types? Date is obviously not xxxx-xx-xx and Time is obviously not xx:xx:xx.
There are a few options,
DateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
try {
Date d = sdf.parse("1995-03-07");
System.out.println(d);
} catch (ParseException e) {
e.printStackTrace();
}
Output is
Tue Mar 07 00:00:00 EST 1995
Or, you could use
// -1 because January is 0... I didn't design it!
Calendar c = new GregorianCalendar(1995, 3 - 1, 7);
System.out.println(c.getTime());
with the same output as before.
SimpleDateFormat is what You need. It's need to be initialized by format of date.
Use it like this:
SimpleDateFormat dateFormat = new SimpleDateFormat(
"yyyy/MM/dd HH:mm:ss", Locale.getDefault());
and then:
Date date = (Date) dateFormat.parse("2014/04/02 22:22:22");
Take a look at DateFormat and particularly SimpleDateFormat.
Your example would be coded like this, using SimpleDateFormat:
Date date = new SimpleDateFormat("yyyy-MM-dd").parse("1995-03-07")
(I'm assuming you have months before days here, you will need to interchange the MM and dd if not).
Java does not support Date literals. You need to use a constructor or a static factory method to obtain an instance of this class.
1995-03-07 returns 1985 because you have three int literals here and the hyphens are interpreted as subtraction operators.
Take a look at the documentation for the Date class and the DateFormat class
Here's a way you could represent these values:
SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
Date date = dateFormat.parse("1995-03-07");
SimpleDateFormat timeFormat = new SimpleDateFormat("HH:mm:ss");
Date time = timeFormat.parse("03:46:16");
You can use the same format objects to perform the reverse of this conversion. Please mind that these Date instances represent a specific moment in time, down to millisecond level. Internally, this is represented as the number of milliseconds since January 1, 1970, 00:00:00 GMT
This API is hardly the prettiest one in Java and by looking at the docs you can see how many changes it has undergone. Just look at the number of deprecated methods.
I recommend taking a look at the Joda-Time library instead.
Alternatively, if using Java 8 is an option for you, you can try the brand new API that comes with it
The answer by Tom is correct. No date-time literals inJava.
And as he stated, the old bundled java.util.Date and .Calendar classes are notoriously troublesome. Avoid them. Use either the Joda-Time library or the new java.time package in Java 8.
Joda-Time
In Joda-Time:
If you want only a date without time and time zone, use the LocalDate class.
Similarly to use only time while ignoring time zone and date, use the LocalTime class.
But most often you'll probably want to use the DateTime class which tracks date, time, and time zone all in one object.
A Date-Time Is Not Text
A DateTime object does not contain text. No String. If you need a string representation, use a formatter object to generate one. Search StackOverflow for many examples.
Built into Joda-Time are formatters for the sensible and increasingly common ISO 8601 standard. For example, the toString implementation on the DateTime class produces a String like this…
2014-04-01T20:17:35-08:00
I call a service which returns GMT dates. Its been working fine since November, but now with daylight savings time active, its failing. Here's a sample date from non-daylight savings time:
2011-12-07T15:50:01Z
And one from today (in daylight savings time):
2012-03-26T11:05:01+01:00
Previously I've been using this pattern:
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", Locale.UK);
But its failing on the second date above with a ParseExcepton ("Unparsable date..."). So, can one pattern be used for both, and if so what is it? If I can't use one pattern for both, what is the correct pattern for the second date above?
It shouldn't make a difference, but if it does this is in use on the Android platform.
It definitely makes a difference that you're using Android, as it would make a difference in this case if you were using Java 5/6 or 7.
The pattern you're using specifies a literal 'Z' (also 'T') to be parsed. It is not parsing a timezone. You need to drop the single-quotes from around the 'Z' to start parsing an actual time-zone.
According to the Android JavaDoc, it is unclear whether a capital Z will even work in this case, as the format of the hours/minutes is pretty specific. I don't know enough about the Android SDK to confirm, but the colon definitly makes a difference in standard Java.
The new ISO8601 time zone pattern is covered by the X pattern specifier which is introduced in Java 7.
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssX", Locale.UK);
If you're still on Java 6 or older, then yes it may make difference. You'll need either to parse it (partially) yourself or to grab Joda Time.
In case you use java6, you will have to identify the patterns and then apply the formater
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");
String date2Str="2011-12-07T15:50:01Z";
Date date2 = df.parse(date2Str);
System.out.println(date2.toString());
SimpleDateFormat df2 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssz");
String date1Str="2012-03-26T11:05:01GMT+01:00";
Date date1 = df2.parse(date1Str);
System.out.println(date1.toString());
i have a form where user enters an ad start time and an ad end time, the format of that time is "yyyy/mm/dd hh:mm:ss", then this data is push to a database.
BUT when user enters "yyyy/mm/dd 12:00:00" or basically anything 12, when i use 24 it just doesnt work, the database shows 00:00:00 for when i enter 12. how do i prevent that from happening?
SplashPageValue value = new SplashPageValue();
SimpleDateFormat df = new SimpleDateFormat("yyyy/MM/dd hh:mm:ss");
value.adStartDate = df.parse(fileUp.getString("adStartDate"));
value.adEndDate = df.parse(fileUp.getString("adEndDate"));
screenshots below:
the form
what i see in database using SQuirreL
Your question is unclear, but I strongly suspect the problem is just that you're parsing using the 12-hour clock. Change your format string to use HH instead of hh, and that may well just fix things:
SimpleDateFormat df = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
You should also consider which time zone you want to use when parsing, mind you. Personally I prefer to use Joda Time for all date and time operations in Java - including for parsing/formatting, as SimpleDateFormat isn't thread-safe, unlike Joda Time's parsers.
Your date format should be 24 hours:
SimpleDateFormat df = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Capital H's are 24, lowercase h are 12.
Use HH instead of hh.
http://docs.oracle.com/javase/1.4.2/docs/api/java/text/SimpleDateFormat.html