I'm trying to create a method that prints e.g. actual time of arrival (now) and then it prints the time of departure which I want to set plus 3 minutes compared to the first one.
public void updateTimes(){
SimpleDateFormat sdf = new SimpleDateFormat("H:mm");
this.arrivalTime = new Date();
this.departureTime = this.arrivalTime.plusMinutes(3);
}
Departure time doesn't work as intended.
Any help is welcome.
java.util.Date not have plusMinutes.
It can be better if you use Java 8, with java.time library :
LocalTime arrivalTime = LocalTime.now();//Current time
LocalTime departureTime = arrivalTime.plusMinutes(3);//plus 3 minutes to the time
//Then you can format the time
String result = departureTime.format(DateTimeFormatter.ofPattern("H:mm"));
Another solution using Calendar looks like:
Calendar cal = Calendar.getInstance();
cal.setTime(arrivalTime); // only if different from "now"
cal.add(Calendar.MINUTE, 3);
departureTime = cal.getTime();
I think you can do something like below:
SimpleDateFormat sdf = new SimpleDateFormat("H:mm");
Date date = new Date();
System.out.println("arrival time = " + sdf.format(date));
int min = date.getMinutes();
date.setMinutes(min+3);
System.out.println("departure time = " + sdf.format(date));
Related
I'm new at coding and I want my program to do something if the current time is between 2 times.
Example:
Current time = 8:25AM
If current time is between 8:00AM and 8:50AM, print 'something' into console.
Is there a way for my program to get the current time automatically? Calendar Class?
Please Help!
Matthew
You can get current time instantiating a new java.util.Object
Date current = new Date();
Then you can play with after() and before() methods
Hope this helps,
Alberto
String starttime = "08:00:00";
String endtime = "08:50:00";
SimpleDateFormat format = new SimpleDateFormat("HH:mm:ss");
Date date1 = format.parse(starttime);
Date date2 = format.parse(endtime);
Calendar cal = Calendar.getInstance();
String currenttime = format.format(cal.getTime());
Date datenow = format.parse(currenttime)
if (date1.getTime() < datnow.getTime() && date2.getTIme() > datenow.getTime())
System.out.println("Time is within defined borders.");
I dont have a compiler now . This should work fine .
I was trying to add current time into previous date. But it was adding in current date with time not with previous date.
see my bellow code:
Date startUserDate = ;//this is my previous date object;
startUserDate.setTime(new Date().getTime());// here i'm trying to add current time in previous date.
System.out.println("current time with previous Date :"+startUserDate);
In previous date there is no time and i want to add current time in previous date.I can do this, please help me out.
Use calendar object
Get instance of calendar object and set your past time to it
Date startUserDate = ;
Calendar calendar = Calendar.getInstance();
calendar.settime(startUserDate);
Create new calendar instance
Calendar cal = Calendar.getInstance();
cal.settime(new Date());
format the date to get string representation of time of current date
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
String currentdate = sdf.format(cal.getTime());
split that string to get hour minute and second object
String hh = expiry.split(":")[0];
String mm = expiry.split(":")[1];
String ss = expiry.split(":")[2];
add it to the previous calendar object
calendar .add(Calendar.HOUR_OF_DAY, hh);
calendar .add(Calendar.MINUTE, mm);
calendar .add(Calendar.SECOND, ss);
this date will have current time added to your date
Date newDate = calendar.getTime;
Use Calendar:
first set the date/time of the first calendar object to the old date
object use as second Calendar object to set the current time on the
first calendar object then convert it back to date
as follow:
//E.g. for startUserDate
Date startUserDate = new Date(System.currentTimeMillis() - (24L * 60L * 60L * 1000L) - (60L * 60L * 1000L));//minus 1 day and 1 hour
Calendar calDateThen = Calendar.getInstance();
Calendar calTimeNow = Calendar.getInstance();
calDateThen.setTime(startUserDate);
calDateThen.set(Calendar.HOUR_OF_DAY, calTimeNow.get(Calendar.HOUR_OF_DAY));
calDateThen.set(Calendar.MINUTE, calTimeNow.get(Calendar.MINUTE));
calDateThen.set(Calendar.SECOND, calTimeNow.get(Calendar.SECOND));
startUserDate = calDateThen.getTime();
System.out.println(startUserDate);
The second Calendar object calTimeNow can be replaced with Calendar.getInstance() where it is used.
You can do it using DateFormat and String, here's the solution that you need:
Code:
DateFormat df = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss");
String timeString = df.format(new Date()).substring(10); // 10 is the beginIndex of time here
DateFormat df2 = new SimpleDateFormat("MM/dd/yyyy");
String startUserDateString = df2.format(startUserDate);
startUserDateString = startUserDateString+" "+timeString;
// you will get this format "MM/dd/yyyy HH:mm:ss"
//then parse the new date here
startUserDate = df.parse(startUserDateString);
Explanation:
Just convert the current date to a string and then extract the time from it using .substring() method, then convert your userDate to a string concatenate the taken time String to it and finally parse this date to get what you need.
Example:
You can see it working in this ideone DEMO.
Which takes 02/20/2002 in input and returns 02/20/2002 04:36:14 as result.
java.time
I recommend that you use java.time, the modern Java date and time API, for your date and time work.
ZoneId zone = ZoneId.systemDefault();
LocalDate somePreviousDate = LocalDate.of(2018, Month.NOVEMBER, 22);
LocalTime timeOfDayNow = LocalTime.now(zone);
LocalDateTime dateTime = somePreviousDate.atTime(timeOfDayNow);
System.out.println(dateTime);
When I ran the code just now — 16:25 in my time zone — I got this output:
2018-11-22T16:25:53.253892
If you’ve got an old-fashioned Date object, start by converting to a modern Instant and perform further conversion from there:
Date somePreviousDate = new Date(1_555_555_555_555L);
LocalDate date = somePreviousDate.toInstant().atZone(zone).toLocalDate();
LocalTime timeOfDayNow = LocalTime.now(zone);
LocalDateTime dateTime = date.atTime(timeOfDayNow);
2019-04-18T16:25:53.277947
If conversely you need the result as an old-fashioned Date, also convert over Instant:
Instant i = dateTime.atZone(zone).toInstant();
Date oldfasionedDate = Date.from(i);
System.out.println(oldfasionedDate);
Thu Nov 22 16:25:53 CET 2018
Link
Oracle tutorial: Date Time explaining how to use java.time.
The getTime method returns the number of milliseconds since 1970/01/01 so to get the time portion of the date you can either use a Calendar object or simply use modula arithmetic (using the above milliseconds value and the MAX millseconds in a day) to extract the time portion of the Date.
Then when you have the time you need to add it to the second date,
but seriously, use http://docs.oracle.com/javase/7/docs/api/java/util/Calendar.html
and use things like get (HOUR) and get (MINUTE) etc. which then you can use with set (HOUR, val)
You need to use Calendar class to perform addition to Dateobject. Date's setTime() will set that time in Date object but not add i.e it will overwrite previous date. new Date().getTime() will not return only time portion but time since Epoch. Also, how did you manipulated , startUserDate to not have any time (I mean , was it via Calendar or Formatter) ?
See Answer , Time Portion of Date to calculate only time portion,
long MILLIS_PER_DAY = 24 * 60 * 60 * 1000;
Date now = Calendar.getInstance().getTime();
long timePortion = now.getTime() % MILLIS_PER_DAY;
then you can use something like, cal.add(Calendar.MILLISECOND, (int)timePortion); where cal is Calendar object corresponding to your startUserDate in your code.
Calendar calendar = Calendar.getInstance();
calendar.setTime(startUserDate );
//new date for current time
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
String currentdate = sdf.format(new Date());
String hhStr = currentdate.split(":")[0];
String mmStr = currentdate.split(":")[1];
String ssStr = currentdate.split(":")[2];
Integer hh = 0;
Integer mm = 0;
Integer ss = 0;
try {
hh = Integer.parseInt(hhStr);
mm = Integer.parseInt(mmStr);
ss = Integer.parseInt(ssStr);
}catch(Exception e) {e.printStackTrace();}
calendar.set(Calendar.HOUR_OF_DAY, hh);
calendar.set(Calendar.MINUTE, mm);
calendar.set(Calendar.SECOND, ss);
startUserDate = calendar.getTime();
I am trying to get the system date by using the following code . Now i want after adding 123 minutes it should automatically add 2 in hours and three in minutes how is it possible?
I am using the following code.
try{
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
Date date = new Date();
String s = sdf.format(date);
}
catch(Exception ex)
{
ex.printStackTrace();
}
Create a GregorianCalendar object: http://docs.oracle.com/javase/7/docs/api/java/util/GregorianCalendar.html add you hours/minutes/whatever you need to add and then get back a Date
This will work
DateFormat df = new SimpleDateFormat("HH:mm:ss");
Date date = new Date();
System.out.println(df.format(date));
long milSec=date.getTime();
long addMilSec=123*60*1000;
long sum=milSec+addMilSec;
Date d=new Date(sum);
System.out.println(df.format(d));
Create a Calendar object, instead of Date, and use add.
Example:
Calendar c = Calendar.getInstance();
c.add(Calendar.MINUTE, 123);
String s = sdf.format(c.getTime());
try like this
Calendar now = Calendar.getInstance();
now.setTime(YOUR_DATE_OBJECT);//pass your date here
now.add(Calendar.MINUTE, 50);//add 5o minutes
now.add(Calendar.SECOND, -50);// subtract 50 seconds
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;
}
I have a problem to sort date because of the format of these dates.
I obtain the date :
final Calendar c = Calendar.getInstance();
mYear = c.get(Calendar.YEAR);
mMonth = c.get(Calendar.MONTH);
mDay = c.get(Calendar.DAY_OF_MONTH);
And I build a String with these values.
dateRappDB = (new StringBuilder()
.append(mYear).append(".")
.append(mMonth + 1).append(".")
.append(mDay).append(" ")).toString();
The problem is that if the month is for example February, mMonth value is 2. So dates with months like October (10) comes before in my list.
What I need is that month and day are formated like MM and dd. But I don't know how to do it in my case.
EDIT :
I solved the problem by using a DateFormat like said above.
I replaced this :
dateRappDB = (new StringBuilder()
.append(mYear).append(".")
.append(mMonth + 1).append(".")
.append(mDay).append(" ")).toString();
By this :
Date date = new Date(mYear - 1900, mMonth, mDay);
dateFacDB = DateFormat.format("yyyy.MM.dd", date).toString();
And it works.
Thanks to all of you for your help :)
here is a simple way to convert Date to String :
SimpleDateFormat simpleDate = new SimpleDateFormat("dd/MM/yyyy");
String strDt = simpleDate.format(dt);
Calendar calendar = Calendar.getInstance();
Date now = calendar.getTime();
String timestamp = simpleDateFormat.format(now);
These might come in handy
SimpleDateFormat simpleDateFormat =
new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSSSSZZZZZ");
this format is equal to --> "2016-01-01T09:30:00.000000+01:00"
SimpleDateFormat simpleDateFormat =
new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZZZZZ");
this format is equal to --> "2016-06-01T09:30:00+01:00"
here is the example for date format
SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
Date date = new Date();
System.out.println("format 1 " + sdf.format(date));
sdf.applyPattern("E MMM dd yyyy");
System.out.println("format 2 " + sdf.format(date));
You need to sort dates, not strings. Also, have you heared about DateFormat? It makes all that appends for you.
If I understand your issue, you create a list of dates and since they're strings, they get arranged in a dictionary-order number-wise, which means you get october before february (10 before 2).
If I were you, I would store my results in a container where I control the insertion point (like an array list) or where I can control the sorting algorithm.