1.I want to set the setMaxSelectableDate=18years in JDateChooser so i provided it the date by incrementing milliseconds but how should i increment it by 18years.
2.Incrementing by 18years the calculation comes out to be 365*18*24*60*60*1000=56764800000 which gives me error integer number to large.
Date max=new Date();
Date oth1=new Date(max.getTime() + (365*18*24*60*60*1000)); //days*hours*minutes*seconds*milliseconds
SimpleDateFormat maxdateFormatter1 = new SimpleDateFormat("MMM d,yyyy hh:mm:ss a");
String maxdate=maxdateFormatter1.format(oth1);
DateChooser_V1.setMaxSelectableDate(new java.util.Date(maxdate));
Let java.util.Calendar do this work for you:
Calendar c = Calendar.getInstance();
c.setTime(oldDate);
c.add(Calendar.YEAR, 18);
Date newDate = c.getTime();
Which takes care of leap years, historical GMT offset changes, historical Daylight Saving Time schedule changes etc.
You need to use a long. You can achieve this by adding an L to your number:
365L* ...
With JodaTime
DateTime in18Years = new DateTime( ).plusYears( 18 );
Here is how to convert to java.util.Date
Date in18Years = new DateTime( ).plusYears( 18 ).toDate( );
You cannot willy-nilly add seconds (or millseconds) and expect calendar calculations to come out right. Basically it takes some extra effort to account for all of those leap-years, leap seconds, and daylight savings shifts.
Until Java 1.8 comes out, use java.util.Calendar instead of java.util.Date, there are really good reasons that java.util.Date has practically everything in it deprecated. While it looks good in the beginning, with enough use you will find it often "just doesn't work (tm)".
GregorianCalendar now = new GregorianCalendar();
now.add(Calendar.YEAR, 18);
And that's assuming that you didn't overflow Integer.MAX_INT.
I would use a Calendar object to achieve this:
Calendar cal = Calendar.getInstance();
Date dt = new Date();
...
// Set the date value
...
cal.setTime(dt);
cal.add(Calendar.YEAR, +18);
dt = cal.getTime();
Hope this helps you
Related
I am currently trying to get create a java Date which looks the same no matter what timezone I view it in. My current code is:
Calendar cal = Calendar.getInstance();
cal.set(2015, Calendar.JANUARY, 8, 0, 0, 0);
cal.set(Calendar.MILLISECOND, 0);
Date date = cal.getTime();
In my current timeZone this gives me '2015-01-08T00:00:00Z'In another this gives me 2015-01-08T00:00:00-03:00. What I want to know is if there is any way to drop the timezone part so as the time is the same in both time zones.
I would be VERY grateful for any help on this matter. Thank you.
Java SE 8 comes with a new Date & Time API. Have a look at LocalDate and LocalDateTime.
If you are only interested in the format of the time, create a java.text.SimpleDateFormat object to print your time in the format that you want.
http://docs.oracle.com/javase/1.5.0/docs/api/java/text/SimpleDateFormat.html
If you want the time to be printed with the same numbers no matter the TimeZone,
Use String ids[] = java.util.TimeZone.getAvailableIDs();
to get the TimeZone's IDs and find the ID that you want.
In this example, I created two SimpleDateFormat objects set to two different TimeZones. They both print off the same Calendar object. I have taken off the Z in ft2 to remove the time zone portion. By relying on toString(), I think you would be subject to Locale differences in displaying dates, like US MM/dd/yyyy and UK dd/MM/yyyy.
TimeZone tz = TimeZone.getTimeZone("America/New_York");
TimeZone tz2 = TimeZone.getTimeZone("America/Chicago");
Calendar acal = new GregorianCalendar();
SimpleDateFormat ft = new SimpleDateFormat ("yyyy-MM-dd'T'hh:mm:ss Z");
ft.setTimeZone(tz);
SimpleDateFormat ft2 = new SimpleDateFormat ("yyyy-MM-dd'T'hh:mm:ss");
ft2.setTimeZone(tz2);
String date1 = ft.format(acal.getTime());
System.out.println(date1);
String date2 = ft2.format(acal.getTime());
System.out.println(date2);
Output:
2015-01-08T10:36:39 -0500
2015-01-08T09:36:39
I am running one query on oracle sql which returns me timestamp part of of sysdate in string
something like "16:30:0.0"
so i want to know how to convert it to milliseconds.
please help?
This is using the standard Java Date API.
DateFormat df = new SimpleDateFormat("HH:mm:ss.SSS");
df.setTimeZone(TimeZone.getTimeZone("UTC"));
df.parse("16:06:43.233").getTime();
If you're using Java 8, see the new java.time API. If not, and you're going to do a lot of date-time-related work, see JodaTime
Use ResultSet's getTime(column)-method instead of getString(column) to avoid having to do the conversion yourself: http://docs.oracle.com/javase/7/docs/api/java/sql/ResultSet.html#getTime%28int%29
Try this,
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss.SSS");
Date date = sdf.parse("16:30:0.0");
System.out.println(date.getTime());
But, this code will return milliseconds since 01.01.1970 16:30:00.000. If you want to get millis from the current day you can do the following.
Calendar today = Calendar.getInstance();
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.set(Calendar.YEAR, today.get(Calendar.YEAR));
cal.set(Calendar.MONTH, today.get(Calendar.MONTH));
cal.set(Calendar.DAY_OF_MONTH, today.get(Calendar.DAY_OF_MONTH));
System.out.println(cal.getTimeInMillis());
How to reduce one month from current date and want to sore in java.util.Date variable
im using this code but it's shows error in 2nd line
java.util.Date da = new Date();
da.add(Calendar.MONTH, -1); //error
How to store this date in java.util.Date variable?
Use Calendar:
Calendar cal = Calendar.getInstance();
cal.add(Calendar.MONTH, -1);
Date result = cal.getTime();
Starting from Java 8, the suggested way is to use the Date-Time API rather than Calendar.
If you want a Date object to be returned:
Date date = Date.from(ZonedDateTime.now().minusMonths(1).toInstant());
If you don't need exactly a Date object, you can use the classes directly, provided by the package, even to get dates in other time-zones:
ZonedDateTime dateInUTC = ZonedDateTime.now(ZoneId.of("Pacific/Auckland")).minusMonths(1);
Calendar calNow = Calendar.getInstance()
// adding -1 month
calNow.add(Calendar.MONTH, -1);
// fetching updated time
Date dateBeforeAMonth = calNow.getTime();
you can use Calendar
java.util.Date da = new Date();
Calendar cal = Calendar.getInstance();
cal.setTime(da);
cal.add(Calendar.MONTH, -1);
da = cal.getTime();
Using new java.time package in Java8 and Java9
import java.time.LocalDate;
LocalDate mydate = LocalDate.now(); // Or whatever you want
mydate = mydate.minusMonths(1);
The advantage to using this method is that you avoid all the issues about varying month lengths and have more flexibility in adjusting dates and ranges. The Local part also is Timezone smart so it's easy to convert between them.
As an aside, using java.time you can also get the day of the week, day of the month, all days up to the last of the month, all days up to a certain day of the week, etc.
mydate.plusMonths(1);
mydate.with(TemporalAdjusters.next(DayOfWeek.SUNDAY)).getDayOfMonth();
mydate.with(TemporalAdjusters.lastDayOfMonth());
Using JodaTime :
Date date = new DateTime().minusMonths(1).toDate();
JodaTime provides a convenient API for date manipulation.
Note that similar Date API will be introduced in JDK8 with the JSR310.
You can also use the DateUtils from apache common. The library also supports adding Hour, Minute, etc.
Date date = DateUtils.addMonths(new Date(), -1)
raduce 1 month of JDF
Date dateTo = new SimpleDateFormat("yyyy/MM/dd").parse(jdfMeTo.getJulianDate());
Calendar cal = Calendar.getInstance();
cal.setTime(dateTo);
cal.add(Calendar.MONTH, -1);
Date dateOf = cal.getTime();
Log.i("dateOf", dateOf.getTime() + "");
jdfMeOf.setJulianDate(cal.get(Calendar.DAY_OF_YEAR), cal.get(Calendar.DAY_OF_MONTH),
cal.get(Calendar.DAY_OF_WEEK_IN_MONTH));
I have a GregorianCalendar that I am am trying to set the time on. I am getting the date from one calendar and the time from another calendar. It mostly works, except for the 2AM hour of the DST switch day.
For example, with a date of 3/10/2013, a time of 2:40AM and a target output of 3/10/2013 2:40AM, I get 3/10/2013 3:40AM:
GregorianCalendar reportingDate = //some instance with a relevant date (in this case 3/10/2013)
GregorianCalendar targetTime = //some instance with a relevant time (in this case 2:40AM)
Calendar combination = Calendar.getInstance();
combination.set(Calendar.YEAR, reportingDate.get(Calendar.YEAR));
combination.set(Calendar.MONTH, reportingDate.get(Calendar.MONTH));
combination.set(Calendar.DAY_OF_YEAR, reportingDate.get(Calendar.DAY_OF_YEAR));
combination.set(Calendar.HOUR, targetTime.get(Calendar.HOUR));
combination.set(Calendar.AM_PM, targetTime.get(Calendar.AM_PM));
combination.set(Calendar.MINUTE, targetTime.get(Calendar.MINUTE));
combination.set(Calendar.SECOND, targetTime.get(Calendar.SECOND));
As soon as the code sets the AM_PM on the combination Calendar the time switches to 3:40AM. I would like it to not switch. I think this has to do with the target time Calendar being created as a time on the epoch date, but I would like the target time's specific date to not really matter...
Based on this output... I would think this is just how Java deals with DST? Seems like 2-3 AM goes into oblivion
See my comment below
final Calendar reportingDate = Calendar.getInstance();
reportingDate.set(Calendar.YEAR, 2013);
reportingDate.set(Calendar.MONTH, Calendar.MARCH);
reportingDate.set(Calendar.DAY_OF_MONTH, 10);
final Calendar targetTime = Calendar.getInstance();
targetTime.set(Calendar.AM_PM, Calendar.AM);
targetTime.set(Calendar.HOUR_OF_DAY, 3);
targetTime.set(Calendar.MINUTE, 0);
targetTime.set(Calendar.SECOND, 0);
targetTime.set(Calendar.MILLISECOND, 0);
final Calendar combination = Calendar.getInstance();
combination.set(Calendar.YEAR, reportingDate.get(Calendar.YEAR));
combination.set(Calendar.MONTH, reportingDate.get(Calendar.MONTH));
combination.set(Calendar.DAY_OF_YEAR, reportingDate.get(Calendar.DAY_OF_YEAR));
combination.set(Calendar.HOUR, targetTime.get(Calendar.HOUR));
combination.set(Calendar.AM_PM, targetTime.get(Calendar.AM_PM));
combination.set(Calendar.MINUTE, targetTime.get(Calendar.MINUTE));
combination.set(Calendar.SECOND, targetTime.get(Calendar.SECOND));
combination.set(Calendar.MILLISECOND, targetTime.get(Calendar.MILLISECOND));
final long timeAtCombined = combination.getTimeInMillis();
final SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss.SSSZ");
sdf.setTimeZone(TimeZone.getTimeZone("US/Eastern"));
// subtract one minute
System.out.println(sdf.format(combination.getTime()));
combination.add(Calendar.MILLISECOND, -1);
System.out.println(sdf.format(combination.getTime()));
// millis # 3
System.out.println(sdf.format(new Date(timeAtCombined)));
// millis # 3 - 1ms
System.out.println(sdf.format(new Date(timeAtCombined - 1)));
Output
03/10/2013 03:00:00.000-0400
03/10/2013 01:59:59.999-0500
03/10/2013 03:00:00.000-0400
03/10/2013 01:59:59.999-0500
You're setting everything, except for the time zone (which contains the DST). Set that as well, and you should be okay.
This isn't really an answer to your question directly but you can avoid all of this craziness by going with Joda Time
They have really nailed the date/time/calendar thing down.
I want to do something like:
Date date = new Date(); // current date
date = date - 300; // substract 300 days from current date and I want to use this "date"
How to do it?
Java 8 and later
With Java 8's date time API change, Use LocalDate
LocalDate date = LocalDate.now().minusDays(300);
Similarly you can have
LocalDate date = someLocalDateInstance.minusDays(300);
Refer to https://stackoverflow.com/a/23885950/260990 for translation between java.util.Date <--> java.time.LocalDateTime
Date in = new Date();
LocalDateTime ldt = LocalDateTime.ofInstant(in.toInstant(), ZoneId.systemDefault());
Date out = Date.from(ldt.atZone(ZoneId.systemDefault()).toInstant());
Java 7 and earlier
Use Calendar's add() method
Calendar cal = Calendar.getInstance();
cal.setTime(dateInstance);
cal.add(Calendar.DATE, -30);
Date dateBefore30Days = cal.getTime();
#JigarJoshi it's the good answer, and of course also #Tim recommendation to use .joda-time.
I only want to add more possibilities to subtract days from a java.util.Date.
Apache-commons
One possibility is to use apache-commons-lang. You can do it using DateUtils as follows:
Date dateBefore30Days = DateUtils.addDays(new Date(),-30);
Of course add the commons-lang dependency to do only date subtract it's probably not a good options, however if you're already using commons-lang it's a good choice. There is also convenient methods to addYears,addMonths,addWeeks and so on, take a look at the api here.
Java 8
Another possibility is to take advantage of new LocalDate from Java 8 using minusDays(long days) method:
LocalDate dateBefore30Days = LocalDate.now(ZoneId.of("Europe/Paris")).minusDays(30);
Simply use this to get date before 300 days, replace 300 with your days:
Date date = new Date(); // Or where ever you get it from
Date daysAgo = new DateTime(date).minusDays(300).toDate();
Here,
DateTime is org.joda.time.DateTime;
Date is java.util.Date
Java 8 Time API:
Instant now = Instant.now(); //current date
Instant before = now.minus(Duration.ofDays(300));
Date dateBefore = Date.from(before);
As you can see HERE there is a lot of manipulation you can do. Here an example showing what you could do!
DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Calendar cal = Calendar.getInstance();
//Add one day to current date.
cal.add(Calendar.DATE, 1);
System.out.println(dateFormat.format(cal.getTime()));
//Substract one day to current date.
cal = Calendar.getInstance();
cal.add(Calendar.DATE, -1);
System.out.println(dateFormat.format(cal.getTime()));
/* Can be Calendar.DATE or
* Calendar.MONTH, Calendar.YEAR, Calendar.HOUR, Calendar.SECOND
*/
With Java 8 it's really simple now:
LocalDate date = LocalDate.now().minusDays(300);
A great guide to the new api can be found here.
In Java 8 you can do this:
Instant inst = Instant.parse("2018-12-30T19:34:50.63Z");
// subtract 10 Days to Instant
Instant value = inst.minus(Period.ofDays(10));
// print result
System.out.println("Instant after subtracting Days: " + value);
I have created a function to make the task easier.
For 7 days after dateString: dateCalculate(dateString,"yyyy-MM-dd",7);
To get 7 days upto dateString: dateCalculate(dateString,"yyyy-MM-dd",-7);
public static String dateCalculate(String dateString, String dateFormat, int days) {
Calendar cal = Calendar.getInstance();
SimpleDateFormat s = new SimpleDateFormat(dateFormat);
try {
cal.setTime(s.parse(dateString));
} catch (ParseException e) {
e.printStackTrace();
}
cal.add(Calendar.DATE, days);
return s.format(cal.getTime());
}
You may also be able to use the Duration class. E.g.
Date currentDate = new Date();
Date oneDayFromCurrentDate = new Date(currentDate.getTime() - Duration.ofDays(1).toMillis());
You can easily subtract with calendar with SimpleDateFormat
public static String subtractDate(String time,int subtractDay) throws ParseException {
Calendar cal = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm", Locale.ENGLISH);
cal.setTime(sdf.parse(time));
cal.add(Calendar.DATE,-subtractDay);
String wantedDate = sdf.format(cal.getTime());
Log.d("tag",wantedDate);
return wantedDate;
}