How to get current month from the selected date in GWT? - gwt

Date startDate = new Date(Long.valueOf(""05/07/2018")getValue().toString());
get last day of selected month is required
private Date lastDayOfMonth(Date month) {
Date lastDay = (Date) month.clone();
CalendarUtil.addMonthsToDate(lastDay, 1);
CalendarUtil.setToFirstDayOfMonth(lastDay);
CalendarUtil.addDaysToDate(lastDay, -1);
GWT.log("lastDay :: "+lastDay);
return lastDay;
}
I get lastDay :: Tue Jul 31 00:00:00 GMT+530 2018
But i get 30th instead of 31st

First, your code does not work
Date startDate = new Date(Long.valueOf(""05/07/2018")getValue().toString());
Second, your method private Date lastDayOfMonth(Date month) looks fine, I have a test and got result Tue Jul 31 00:00:00
I dont understand your problem "Tue Jul 31 00:00:00 GMT+530 2018 But i get 30th instead of 31st". How can you get 30th from Tue Jul 31 00:00:00 GMT+530?

Related

Truncate date to start of the day in a given timeZone

I am looking to truncate the date time to start of the day for the given timeZone.
If the current time is Mon Aug 24 15:38:42 America/Los_Angeles, it should be truncated to start of the day Mon Aug 24 00:00:00 America/Los_Angeles which then later should be converted to equivalent UTC time.
I have explored the methods provided by Joda Time Library, Apache Commons Library and ZonedDateTime but all of them truncate the date time in UTC and not to specific timeZone.
Can someone help me with this? Thanks in advance.
You can use ZonedDateTime. Use toLocalDate() on ZonedDateTime to get LocalDate then atStartOfDay on LocalDate with zone of ZonedDateTime instance to get the start of day.
Example:
ZonedDateTime now = ZonedDateTime.now(ZoneId.of("America/Los_Angeles"));
ZonedDateTime startOfDay = now.toLocalDate().atStartOfDay(now.getZone());
DateTimeFormatter formatter = DateTimeFormatter.RFC_1123_DATE_TIME;
System.out.println(now.format(formatter)); // Mon, 24 Aug 2020 10:41:41 -0700
System.out.println(startOfDay.format(formatter)); // Mon, 24 Aug 2020 00:00:00 -0700
ZonedDateTime truncates in its own time zone. So it can be done a bit simpler than in the currently accepted answer (which is also a good and correct answer).
ZonedDateTime given = ZonedDateTime.of(2020, 8, 24, 15, 38, 42, 0, ZoneId.of("America/Los_Angeles"));
ZonedDateTime startOfDay = given.truncatedTo(ChronoUnit.DAYS);
System.out.println("Truncated to start of day: " + startOfDay);
Instant inUtc = startOfDay.toInstant();
System.out.println("In UTC: " + inUtc);
Output is:
Truncated to start of day: 2020-08-24T00:00-07:00[America/Los_Angeles]
In UTC: 2020-08-24T07:00:00Z

Date minus date is not giving desired answer - IONIC 2

When I try to subtract
Wed Dec 06 2017 15:58:59 GMT+0530 (India Standard Time) minus Tue Nov 28 2017 00:00:00 GMT+0530 (India Standard Time) , the answer which is coming is -22
But the answer should be 6
What is going wrong and where, below is my page.ts code:
this.tt = new Date();
this.tt1 = this.datePipe.transform(this.tt,'dd/mm/yyyy');
console.log(this.ent[0],"server DATE");
// in console we see this - 28-NOV-17 server DATE
var firstDate= new Date(this.ent[0]); //Jan 01 2017 00:00:00
var secondDate = new Date();//Jan 04 2017 00:00:00
console.log(firstDate);
// answer in console - Tue Nov 28 2017 00:00:00 GMT+0530 (India Standard Time)
console.log(secondDate);
//answer in console - Wed Dec 06 2017 15:58:59 GMT+0530 (India Standard Time)
console.log(secondDate.getDate() - firstDate.getDate() );
//answer in console - -22
Date.getDate() gives the "dd" of the date (in your case 6 and 28 which explains the result being -22).
I'm a bit confused with the expected result being 6. So maybe my answer won't fit you. What I would do however is convert the date in time, do the substraction and convert it back to number of days.
So
Math.Floor((secondDate.getTime() - firstDate.getTime()) / 86400000);
(86400000 being 1000 (milliseconds) * 3600 (seconds in an hour) * 24 (number of hours in a day)
you can convert both dates to timestamp and subtract the timestamp you will get the result days in millis now convert it to days
getTimestamp(dateParam:string):string{
var date = new Date(dateParam); // some mock date
var milliseconds = date.getTime();
return milliseconds.toString();
}
var one_day=1000*60*60*24;
console.log(Math.ceil(getTimestamp(secondDate) - getTimestamp(firstDate))/(one_day) );

How to format a date in Ext JS 3?

I have a date value like this ;
Date {Fri Feb 13 2015 02:00:00 GMT+0200 (GTB Standart Saati)}
I get it from a grid column with ;
selectionModel.getSelected().data['date'];
And column model date format is 'd/m/Y'. It shows in grid well (d/m/Y).But when i get selected value it returns a date format doesn't like 'd/m/Y'. How can i format this date to set to a textfield ?
According to ExtJs Docs
var d = new Date(1993, 6, 28, 14, 39, 7);
println(d.toString()); // prints Wed Jul 28 1993 14:39:07 GMT-0600 (PDT)
println(d.toDateString()); // prints Wed Jul 28 1993
Edit:
Please use Ext.Date.format to format the date:
Ext.Date.format(d,'d/m/Y');
According to ExtJS 3.4 Docs Date object is extended with .format() method.
So you should be able to just do
var d = new Date();
d.format("d/m/Y");

Difference between two isodates in mongo

If I have two ISODates such as:
Tue Sep 18 1984 00:00:00 GMT+0100 (CET)
and
Sat Jun 21 2014 10:00:00 GMT+0100 (CET)
how do I get a difference between them using the mongo console? Specifically the difference in years?
they are from different collections so I can't use an aggregation for this.. :(
ISODate() is just a convenient wrapper around a standard JavaScript Date object so you can use the standard Date methods or calculate the difference yourself (date values are stored in milliseconds):
> var date1 = ISODate("1984-09-18");
> var date2 = ISODate("2014-06-21");
> date2.getFullYear() - date1.getFullYear()
30
> var yearMS = 365 * 24 * 60 * 60 * 1000; // a year in milliseconds
> parseFloat((date2-date1)/yearMS).toFixed(2)
29.78

Go language time.Parse() for timestamps with no timezone

In Go I'm trying to use the time.Parse() function from the time package to convert a string timestamp into a Time object. I know Go has an uncommon way of representing the time format your timestamps are in by providing it with an example of how their reference time (Mon Jan 2 15:04:05 -0700 MST 2006) would be displayed in your format. I'm still having issues with errors however. Here is an example of one of my timestamps:
Tue Nov 27 09:09:29 UTC 2012
Here is what the call I'm making looks like:
t, err := time.Parse("Mon Jan 02 22:04:05 UTC 2006", "Tue Nov 27 09:09:29 UTC 2012")
So basically what I've done here is try and match the formatting for day name/month name/day number, the hour/minute/second format, the string literal "UTC" and the year format. Note that I've increased the hours field of the Go reference format by 7 (from 15 to 22) to account for the fact that their timestamp is in a negative 7 timezone and all my timestamps are in a UTC timezone.
The error I get is:
parsing time "Tue Nov 27 09:09:29 UTC 2012" as "Mon Jan 02 22:04:05 UTC 2006": cannot parse ":09:29 UTC 2012" as "2"
What am I doing wrong here? Am I misinterpreting how to use time.Parse() or is my use case not supported for some reason?
Your format string should be:
Mon Jan 02 15:04:05 MST 2006
playground
That is, use MST for the timezone and 15 for the hour, as documented in your linked Parse function.
In this case, you can use time.UnixDate:
package main
import (
"fmt"
"time"
)
func main() {
t, e := time.Parse(time.UnixDate, "Tue Nov 27 09:09:29 UTC 2012")
if e != nil {
panic(e)
}
fmt.Println(t)
}
https://golang.org/pkg/time#UnixDate