Timestamp to Date issue - java

I'm trying to create a function that convert a timestamp to Date object.
My problem is that using this online tools i reach correctly to convert timestamp to date but using java it doesn't convert correctly.
This is what i try:
public static Date getDateFromUUID(UUID uuid) {
Calendar uuidEpoch = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
uuidEpoch.clear();
uuidEpoch.set(1582, 9, 15, 0, 0, 0);
long epochMillis = uuidEpoch.getTime().getTime();
long time = (uuid.timestamp() / 10000L) + epochMillis;
Calendar start = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
Calendar end = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
start.setTimeInMillis(time*1000);
end.set(start.get(Calendar.YEAR), start.get(Calendar.MONTH), start.get(Calendar.DAY_OF_MONTH),0,0,0);
return end.getTime();
}
I'm trying using that uuid: a261ae00-2a9c-11b2-ae56-bcee7be23398
it correctly converts to timestamp : 1406412000
Using this:
Calendar start = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
Calendar end = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
start.setTimeInMillis(time*1000);
end.set(start.get(Calendar.YEAR), start.get(Calendar.MONTH), start.get(Calendar.DAY_OF_MONTH),0,0,0);
return end.getTime();
I need to remove hours, minutes and seconds and take only years,months and days.
but it convert timestamp to
Sat Jul 26 02:00:00 CEST 2014
Instead of
Sun Jul 27 00:00:00 CEST 2014
what could be my mistake?
Thanks!

Your time zone if wrong. Notice that output is CEST but you set the calendar to UTC. The delta between these two is 2 hours. When you output the Date you need to set the timezone appropriately.

Related

How to get selected month last date last timestamp in java?

From the below java code I'm getting a month First & last dateTimestamp, but here i need last dateTimestamp as - "Mon Aug 31 23:59:59 IST 2015" instead of - "Mon Aug 31 00:00:00 IST 2015"?
Calendar cal = Calendar.getInstance();
int year = 2015;
int month = 07;
cal.set(cal.DATE,1);
cal.set(cal.YEAR,year);
cal.set(cal.MONTH, month);
String firstDate = (cal.getActualMinimum(cal.DATE) + "/" + (month+1) + "/" +year);
System.out.println("firstDate-->"+"\t"+firstDate);
String lastDate = (cal.getActualMaximum(cal.DATE) + "/" + (month+1) + "/" +year);
System.out.println("lastDate-->"+"\t"+lastDate);
DateFormat firstFormat = new SimpleDateFormat("dd/MM/yyyy");
Date beginDate = firstFormat.parse(firstDate);
System.out.println("BeginDate Timestamp"+ "\t" + beginDate);
DateFormat secoundFormat = new SimpleDateFormat("dd/MM/yyyy");
Date endDate = secoundFormat.parse(lastDate);
System.out.println("endDate Timestamp"+ "\t" + endDate);
Output:->
firstDate--> 1/8/2015
lastDate--> 31/8/2015
BeginDate Timestamp Sat Aug 01 00:00:00 IST 2015
endDate Timestamp Mon Aug 31 00:00:00 IST 2015
Please help me if we have any solution.
If I understand your question, it looks as if you want to pass a year and month into a method, and get back the last day of the passed month.
I would suggest consider (in this order):
which jdk you use
configuration of calendar
configuration of timezone (maybe)
using jodatime
As of 1.8 many JodaTime-like features have been added to the jdk- e.g. see https://docs.oracle.com/javase/8/docs/api/java/time/format/DateTimeFormatter.html (If you arent using 1.8 you can use the joda lib, assuming your organization allows it)
Calendar.getInstance() gives a default TimeZone and a default Locale, which means the definitions of the running JVM. You may or may not need to consider this and implement more than just getInstance(). See API javadoc.
Assuming a Gregeorian Calendar (hey, you could be Bahaian and have 19 months in the year ...) , here is one partial implementation using JDK 1.7, JodaTime jar 2.2, validation-1.0.0.GA jar:
#Test
public void testDate() {
final String dateStringOfFirstDay = "1.7.2015";
final Date lastDayOfMonth = getLastDayOfMonth(dateStringOfFirstDay);
Assert.assertNotNull(lastDayOfMonth);
//more assertions ...
}
private Date getLastDayOfMonth(#NotNull String dateStringOfFirstDay) {
//further validation here necessary according to required date format
DateTime dt = DateTime.parse(dateStringOfFirstDay);
return dt.dayOfMonth().withMaximumValue().toDate();
}
The defintion of DateFormat/DateTimeFormat and further result assertions is left up to you.
Best of luck!
Guys I got a solution for my question!!!
I think it will help u too...
Calendar calendar = Calendar.getInstance();
int year=2015;
int month=7;
int date=31;
int hourOfDay=23;
int minute=59;
int second=59;
int milliSecond=999;
calendar.set(year, month, date, hourOfDay, minute, second);
calendar.set(calendar.MILLISECOND, milliSecond);
System.out.println("Time from Calendar: "+calendar.getTime());
long timeInMilliSeconds=calendar.getTimeInMillis();
System.out.println("timeInMilliSeconds from calendar: "+timeInMilliSeconds);
Timestamp timestamp=new Timestamp(timeInMilliSeconds);
System.out.println(timestamp);
The above program gives the last date last timestamp in a selected month.
getTimeInMillis() takes the time from Jan 01, 1970 to current time in Milliseconds.
Using those milliseconds i'm getting the Timestamp.
Thank you for your help guys!!!
OutPut:->
Time from Calendar: Mon Aug 31 23:59:59 IST 2015
timeInMilliSeconds from calendar: 1441045799999
2015-08-31 23:59:59.999

Using Date in Java

I have various Date instances in my Java program. Working with the is a pain but it is required.
Date today = new Date(); // Wed Dec 10 14:10:29 EST 2014
Date a = new GregorianCalendar(2014, 11, 10).getTime();
Date b = new GregorianCalendar(2015, 01, 10).getTime();
Date c = new GregorianCalendar(2015, 02, 10).getTime();
Date d = new GregorianCalendar(2015, 03, 10).getTime(); //Fri April 10 00:00:00 EDT 2015
Date e = new GregorianCalendar(2015, 11 ,10).getTime();
I need to figure out how to shave off the time (14:10:29) from each as well as convert them to GMT time.
I know today.getTime(); will the number of milliseconds since January 1, 1970, 00:00:00 GMT, but I'm not sure how to represent that with out the times.
This would be for easier comparisons between dates. Thanks.
try using date formater
SimpleDateFormat df= new SimpleDateFormat("HH:MM:ss");
df.format(date)
All you have to do is modulus the long value by the long value of 1 day, and subtract that off the long value of your date.
If you have Wed Dec 10 14:10:29 EST 2014, then if you do
Date today = new Date(); // Wed Dec 10 14:10:29 EST 2014
long timeDiff = today.getTime() % 24 * 60 * 60 * 1000;
today = new Date(today.getTime - timeDiff);
The new today object will be created with the time of the day removed.
To convert them to GMT you can similarly create new dates for the longs. This is obviously "Date" way to do it. The best way would be to use Calendar.

How to convert CET time to local time on device?

I have three different times:
time on server - "Wed, 19 Feb 2014 11:44 CET"
time of start meeting on server - "12:00h"
time on device- "13:49"
I need to get time of start meeting on device ...this-> "14:00h" or time to meeting this-> "11m"
I'm trying to get it by using :
long ts = System.currentTimeMillis();
Date localTime = new Date(ts);
String gmt_time="12:00h";
SimpleDateFormat format = new SimpleDateFormat("HH:mm'h'");
format.setTimeZone(TimeZone.getTimeZone("GMT"));
Date d_date = null;
d_date = format.parse(gmt_time);
format.setTimeZone(TimeZone.getTimeZone("UTC"));
Date fromGmt = new Date(d_date.getTime() + TimeZone.getDefault().getOffset(localTime.getTime()));
String new_date=format.format(fromGmt);
But result in new_date is "15:00h" (I need "14:00h")
You assumption of CET = GMT on Wed, 19 Feb 2014 seems to be incorrect - refer to here.
CET is an hour ahead of GMT
11:44 CET would mean 10:44 GMT
Hence, when you calculate an offset from GMT time and your local time, it adds an hour to it.
Change format.setTimeZone(TimeZone.getTimeZone("GMT")); to format.setTimeZone(TimeZone.getTimeZone("CET")); and it should work as expected.
Found quickly solution
String cet_time="12.11.14"+" "+"12:00h";
SimpleDateFormat format = new SimpleDateFormat("dd.MM.yy' 'HH:mm'h'");
format.setTimeZone(TimeZone.getTimeZone("CET"));
Date d_date = format.parse(cet_time);
( new SimpleDateFormat("dd.MM.yy")).format(fromGmt);//new date String
( new SimpleDateFormat("HH:mm'h'")).format(fromGmt);//new time String

Grab exact date without timezone interfering with XMLGregorianCalendar in Java

I have a XMLGregorianCalendar that I would like to convert to a Java Date object, but when I try to covert this:
2013-11-19T00:00:00-00:00
I always get a date with the value a day behind.
Mon Nov 18 17:00:00 MST 2013
I just want a date object containing 11/19/2013.
As commented above, the result you're getting is right - it's the same moment in time. Midnight UTC is 5PM MST the day before. Perhaps you should look into why your time is in "-00:00" instead of "-07:00" (MST)... but in the meanwhile, I suppose you could try this:
public static void main(String... args) throws DatatypeConfigurationException {
XMLGregorianCalendar xcal = DatatypeFactory.newInstance().newXMLGregorianCalendar("2013-11-19T00:00:00-00:00");
Calendar c = xcal.toGregorianCalendar();
c.setTimeZone(TimeZone.getDefault());
Date d = c.getTime();
System.out.println(d);
}
prints out Tue Nov 19 00:00:00 EST 2013, and will work for other times of day, not just midnight.
I just did this,
Date startDate = new Date(request.getStartTime().getYear(), request.getStartTime().getMonth(), request.getStartTime().getDay(), 0, 0, 0);

Get Previous Day [duplicate]

This question already has answers here:
Closed 13 years ago.
Possible Duplicate:
How to determine the date one day prior to a given date in Java?
If I have a Java.Util.Date object, what is the best way to get an object representing the 24 hours in the past of it?
Using Java 1.6 java.util.Calendar.add:
public static Date subtractDay(Date date) {
Calendar cal = Calendar.getInstance();
cal.setTime(date);
cal.add(Calendar.DAY_OF_MONTH, -1);
return cal.getTime();
}
Others suggest using Joda Time, which is currently JSR 310, and should later be included in Java itself.
The important thing to remember is that the Date class should represent any points in time whilst the Calendar class is used to manipulate those points in time. Last of all, SimpleDateFormat will represent them as Strings.
So, the best way is to use the Calendar class to calculate the new Date for you. This will ensure that any vagaries (Daylight Saving, Leap Years and the like) are accounted for.
I'm assuming that you don't really want to find '24 Hours previous' but actually do want a new Date instance representing 'this time yesterday' - either way, you can ask the Calendar instance for a Date 24Hours prior to another or 1 Day prior.
The Daylight savings is a great example. The UK 'sprang forward' on the 26th March 2009. So, 1 day prior to 3.00a.m. on the 26.Mar.2009 should yield 3.00a.m. 25.Mar.2009 but 24 Hrs prior will yield 2.00a.m.
public class DateTests extends TestCase {
private static String EXPECTED_SUMMER_TIME = "2009.Mar.29 03:00:00";
private static String EXPECTED_SUMMER_TIME_LESS_DAY = "2009.Mar.28 03:00:00";
private static String EXPECTED_SUMMER_TIME_LESS_24_HRS = "2009.Mar.28 02:00:00";
private static String EXPECTED_SUMMER_TIME_LESS_FURTHER_24_HRS = "2009.Mar.27 02:00:00";
public void testSubtractDayOr24Hours() {
SimpleDateFormat formatter = new SimpleDateFormat("yyyy.MMM.dd HH:mm:SS");
Calendar calendar = Calendar.getInstance();
// Create our reference date, 3.00 a.m. on the day the clocks go forward (they 'went' forward at 02.00)
calendar.clear();
calendar.set(2009, 2, 29, 3, 0);
Date summerTime = calendar.getTime(); // Sun Mar 29 03:00:00 BST 2009
String formattedSummerTime = formatter.format(summerTime);
calendar.add(Calendar.DAY_OF_MONTH, -1);
// Our reference date less 'a day'
Date summerTimeLessADay = calendar.getTime(); // Sat Mar 28 03:00:00 GMT 2009
String formattedSummerTimeLessADay = formatter.format(summerTimeLessADay);
// reset the calendar instance to the reference day
calendar.setTime(summerTime);
// Our reference date less '24 hours' (is not quite 24 hours)
calendar.add(Calendar.HOUR, -24);
Date summerTimeLess24Hrs = calendar.getTime(); // Sat Mar 28 02:00:00 GMT 2009
String formattedSummerTimeLess24Hrs = formatter.format(summerTimeLess24Hrs);
// Third date shows that taking a further 24 hours from yields expected result
calendar.add(Calendar.HOUR, -24);
Date summerTimeLessFurther24Hrs = calendar.getTime(); // Fri Mar 27 02:00:00 GMT 2009
String formattedSummerTimeLessFurther24Hrs = formatter.format(summerTimeLessFurther24Hrs);
// reset the calendar once more to the day before
calendar.setTime(summerTimeLess24Hrs);
// Take a 'day' from the Sat will yield the same result as date 03 because Daylight Saving is not a factor
calendar.add(Calendar.DAY_OF_MONTH, -1);
Date summerTimeLessFurtherDay = calendar.getTime(); // Fri Mar 27 02:00:00 GMT 2009
String formattedSummerTimeLessFurtherDay = formatter.format(summerTimeLessFurtherDay);
assert(formattedSummerTime.equals(EXPECTED_SUMMER_TIME));
assert(formattedSummerTimeLessADay.equals(EXPECTED_SUMMER_TIME_LESS_DAY));
assert(formattedSummerTimeLess24Hrs.equals(EXPECTED_SUMMER_TIME_LESS_24_HRS));
assert(formattedSummerTimeLessFurther24Hrs.equals(EXPECTED_SUMMER_TIME_LESS_FURTHER_24_HRS));
// This last test proves that taking 24 hors vs. A Day usually yields the same result
assert(formattedSummerTimeLessFurther24Hrs.equals(formattedSummerTimeLessFurtherDay));
}
}
For testing date functions, wwwdot-timeanddate-dot-com is a great resource.
subtract 1000*60*60*24 from the time and create a new date.
Date yesterday = new Date(d.getTime() - (1000*60*60*24));
int dayInMs = 1000 * 60 * 60 * 24;
Date previousDay = new Date(olddate.getTime() - dayInMs);
Personally if there are a lot of time/date calculations, I'd go with Joda-time.

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