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How to compare two dates in Java by incrementing Date? [duplicate]

This question already has answers here:
How can I increment a date by one day in Java?
(32 answers)
How to compare dates in Java? [duplicate]
(11 answers)
Closed 2 years ago.
How to compare two dates in Java by incrementing Date?
String dt = "2008-01-01"; // Start date
String et="2008-01-10";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar c = Calendar.getInstance();
Date startDate=sdf.parse(dt);
Date endDate=sdf.parse(et);
Date incDate;
// dt is now the new date
do
{
System.out.println("hey i am called.....");
c.setTime(sdf.parse(dt));
c.add(Calendar.DATE, 1); // number of days to add
dt = sdf.format(c.getTime());
System.out.println("Incremet Date"+dt);
incDate=sdf.parse(dt);
}
while(endDate.compareTo(incDate)>=0);

first you should start using the newer classes like #TomStroemer pointed out.
I think you want to get the number of days between the two dates ?
LocalDate startDate = LocalDate.parse("2008-01-01");
LocalDate endDate = LocalDate.parse("2008-01-10");
Period period = Period.between(startDate, endDate);
System.out.println(period.getDays());
Should print 8 because there are 8 days between. Haven't tested that code.
See the following docs:
Period: https://docs.oracle.com/javase/8/docs/api/java/time/Period.html
LocalDate: https://docs.oracle.com/javase/8/docs/api/java/time/LocalDate.html
And really provide more details.

Java wrong data format transformation [duplicate]

This question already has answers here:
Get integer value of the current year in Java
(16 answers)
Closed 5 years ago.
I need a Java program that subtracts 5 years from the current year.
Everything is working fine but after I run the program:
DateFormat dateFormat = new SimpleDateFormat("yyyy");
Calendar cal = Calendar.getInstance();
cal.add(Calendar.YEAR,-5);
Date today = new Date();
String start = dateFormat.format(cal.getTime()).toString();
String end = dateFormat.format(today).toString();
double start_doub = Double.parseDouble(start);
double end_doub = Double.parseDouble(end);
System.out.println(start_doub);
System.out.println(end_doub);
The result is:
2012.0
2017.0
I don't know the reason why the program adds .0 after the year?
How can I remove the last part?

Your code look like below
DateFormat dateFormat = new SimpleDateFormat("yyyy");
Calendar cal = Calendar.getInstance();
cal.add(Calendar.YEAR,-5);
Date today = new Date();
String start = dateFormat.format(cal.getTime()).toString();
String end = dateFormat.format(today).toString();
int start_doub = Integer.parseInt(start);
int end_doub = Integer.parseInt(end);
System.out.println(start_doub);
System.out.println(end_doub);

Java SimpleDateFormat.format Throws java.lang.IllegalArgumentException [duplicate]

This question already has answers here:
Android : Error SimpleDateFormat Unknown pattern character 'u'
(3 answers)
Closed 7 years ago.
I need to get "Day number of week" from Date object. I tried to parse the Day number from the Date object as new SimpleDateFormat("u").format(date).
According to the Oracle documentation of the SimpleDateFormat u : Day number of week (1 = Monday, ..., 7 = Sunday)
This is the exception details

Try this to get the day of the date...
Calendar c = Calendar.getInstance();
c.setTime(yourDate);//Replace your date with the date which u have
int dayOfWeek = c.get(Calendar.DAY_OF_WEEK);

Use This
Calendar c = Calendar.getInstance(); //create an instance of Calendar class
int Day = c.get(Calendar.DAY_OF_WEEK); //get current day of the week from the same instance

Convert day of year to Date in java [duplicate]

This question already has answers here:
Get Date based on day count in Java
(7 answers)
Closed 6 years ago.
I got days in year in format 1-366
How do I convert them to actuall date like 12.12. etc.? + how it's with the 29.2.?
Thanks for answer!

Seems easy to do with Calendar:
final Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.DAY_OF_YEAR, 366);
final Date date = new Date(calendar.getTimeInMillis());
And if you want to offset a year for example:
calendar.add(Calendar.YEAR, 1);

You can use joda-time-android:
MutableDateTime mutableDateTime = new MutableDateTime();
mutableDateTime.setYear(2012);
mutableDateTime.setDayOfYear(366);

JAVA how to take a Date and see the day, month, and year? [duplicate]

This question already has answers here:
Adding a number to the day or month or year in a date [duplicate]
(4 answers)
Closed 8 years ago.
I have a assignment for a class where we take in a date then see if the date given is valid. If it is we then add a day onto it. Where I am having trouble is after I check that the date is valid it is saved to
Date appointment = new Date();
appointment = new Date(month, day, year);
Date.advanceDate(appointment);
in a different file called Date.java
public static void advanceDate(Date aDate){
//here is where I need to read the date in aDate
}
After searching online through the Java api I haven't been able to find a way to add a day onto appointment or get the day, month, and year from appointment add a day to that and then save it as a new Date
what I have tried is doing after looking at http://docs.oracle.com/javase/8/docs/api/java/util/Date.html
aDate.getDay();
but eclipse tells me "the method getDate()is undefined for the type Data
aDate.toString();
this doesn't return the month date and year it returns its location in memery
every solution I've found online uses Calender which seems to have replaced Date

I believe you are looking for a Calendar and a DateFormat,
int year = 2015;
int month = Calendar.FEBRUARY; // <-- this is actually a 1.
int date = 8;
DateFormat df = new SimpleDateFormat("yyyy-MM-dd");
Calendar cal = Calendar.getInstance();
cal.set(year, month, date);
cal.add(Calendar.DAY_OF_MONTH, 1);
System.out.println(df.format(cal.getTime()));
Output is
2015-02-09
1FEBRUARY.