[java] How can I increment a date by one day in Java?

I'm working with a date in this format: yyyy-mm-dd.

How can I increment this date by one day?

It's very simple, trying to explain in a simple word. get the today's date as below

Calendar calendar = Calendar.getInstance();
System.out.println(calendar.getTime());// print today's date
calendar.add(Calendar.DATE, 1);

Now set one day ahead with this date by calendar.add method which takes (constant, value). Here constant could be DATE, hours, min, sec etc. and value is the value of constant. Like for one day, ahead constant is Calendar.DATE and its value are 1 because we want one day ahead value.

System.out.println(calendar.getTime());// print modified date which is tomorrow's date

Thanks

It's simple actually. One day contains 86400000 milliSeconds. So first you get the current time in millis from The System by usingSystem.currentTimeMillis() then add the 84000000 milliSeconds and use the Date Class to generate A date format for the milliseconds.

Example

String Today = new Date(System.currentTimeMillis()).toString();

String Today will be 2019-05-9

String Tommorow = new Date(System.currentTimeMillis() + 86400000).toString();

String Tommorow will be 2019-05-10

String DayAfterTommorow = new Date(System.currentTimeMillis() + (2 * 86400000)).toString();

String DayAfterTommorow will be 2019-05-11

If you are using Java 8, java.time.LocalDate and java.time.format.DateTimeFormatter can make this work quite simple.

public String nextDate(String date){
      LocalDate parsedDate = LocalDate.parse(date);
      LocalDate addedDate = parsedDate.plusDays(1);
      DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-mm-dd");
      return addedDate.format(formatter); 
}

Date today = new Date();               
SimpleDateFormat formattedDate = new SimpleDateFormat("yyyyMMdd");            
Calendar c = Calendar.getInstance();        
c.add(Calendar.DATE, 1);  // number of days to add      
String tomorrow = (String)(formattedDate.format(c.getTime()));
System.out.println("Tomorrows date is " + tomorrow);

This will give tomorrow's date. c.add(...) parameters could be changed from 1 to another number for appropriate increment.

Try this method:

public static Date addDay(int day) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(new Date());
        calendar.add(Calendar.DATE, day);
        return calendar.getTime();
}

Construct a Calendar object and use the method add(Calendar.DATE, 1);

I prefer to use DateUtils from Apache. Check this http://commons.apache.org/proper/commons-lang/javadocs/api-2.6/org/apache/commons/lang/time/DateUtils.html. It is handy especially when you have to use it multiple places in your project and would not want to write your one liner method for this.

The API says:

addDays(Date date, int amount) : Adds a number of days to a date returning a new object.

Note that it returns a new Date object and does not make changes to the previous one itself.

Java does appear to be well behind the eight-ball compared to C#. This utility method shows the way to do in Java SE 6 using the Calendar.add method (presumably the only easy way).

public class DateUtil
{
    public static Date addDays(Date date, int days)
    {
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        cal.add(Calendar.DATE, days); //minus number would decrement the days
        return cal.getTime();
    }
}

To add one day, per the question asked, call it as follows:

String sourceDate = "2012-02-29";
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
Date myDate = format.parse(sourceDate);
myDate = DateUtil.addDays(myDate, 1);

You can use this package from "org.apache.commons.lang3.time":

 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
 Date myNewDate = DateUtils.addDays(myDate, 4);
 Date yesterday = DateUtils.addDays(myDate, -1);
 String formatedDate = sdf.format(myNewDate);  

If you want to add a single unit of time and you expect that other fields to be incremented as well, you can safely use add method. See example below:

SimpleDateFormat simpleDateFormat1 = new SimpleDateFormat("yyyy-MM-dd");
Calendar cal = Calendar.getInstance();
cal.set(1970,Calendar.DECEMBER,31);
System.out.println(simpleDateFormat1.format(cal.getTime()));
cal.add(Calendar.DATE, 1);
System.out.println(simpleDateFormat1.format(cal.getTime()));
cal.add(Calendar.DATE, -1);
System.out.println(simpleDateFormat1.format(cal.getTime()));

Will Print:

1970-12-31
1971-01-01
1970-12-31

Just pass date in String and number of next days

 private String getNextDate(String givenDate,int noOfDays) {
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
        Calendar cal = Calendar.getInstance();
        String nextDaysDate = null;
    try {
        cal.setTime(dateFormat.parse(givenDate));
        cal.add(Calendar.DATE, noOfDays);

       nextDaysDate = dateFormat.format(cal.getTime());

    } catch (ParseException ex) {
        Logger.getLogger(GR_TravelRepublic.class.getName()).log(Level.SEVERE, null, ex);
    }finally{
    dateFormat = null;
    cal = null;
    }

    return nextDaysDate;

}

SimpleDateFormat dateFormat = new SimpleDateFormat( "yyyy-MM-dd" );
Calendar cal = Calendar.getInstance();
cal.setTime( dateFormat.parse( inputString ) );
cal.add( Calendar.DATE, 1 );

Date newDate = new Date();
newDate.setDate(newDate.getDate()+1);
System.out.println(newDate);

Please note that this line adds 24 hours:

d1.getTime() + 1 * 24 * 60 * 60 * 1000

but this line adds one day

cal.add( Calendar.DATE, 1 );

On days with a daylight savings time change (25 or 23 hours) you will get different results!

java.time

On Java 8 and later, the java.time package makes this pretty much automatic. (Tutorial)

Assuming String input and output:

import java.time.LocalDate;

public class DateIncrementer {
  static public String addOneDay(String date) {
    return LocalDate.parse(date).plusDays(1).toString();
  }
}

With Java SE 8 or higher you should use the new Date/Time API

 int days = 7;       
 LocalDate dateRedeemed = LocalDate.now();
 DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd/MM/YYYY");

 String newDate = dateRedeemed.plusDays(days).format(formatter);   
 System.out.println(newDate);

If you need to convert from java.util.Date to java.time.LocalDate, you may use this method.

  public LocalDate asLocalDate(Date date) {
      Instant instant = date.toInstant();
      ZonedDateTime zdt = instant.atZone(ZoneId.systemDefault());
      return zdt.toLocalDate();
  }

With a version prior to Java SE 8 you may use Joda-Time

Joda-Time provides a quality replacement for the Java date and time classes and is the de facto standard date and time library for Java prior to Java SE 8

   int days = 7;       
   DateTime dateRedeemed = DateTime.now();
   DateTimeFormatter formatter = DateTimeFormat.forPattern("dd/MM/uuuu");
        
   String newDate = dateRedeemed.plusDays(days).toString(formatter);   
   System.out.println(newDate);

In java 8 you can use java.time.LocalDate

LocalDate parsedDate = LocalDate.parse("2015-10-30"); //Parse date from String
LocalDate addedDate = parsedDate.plusDays(1);   //Add one to the day field

You can convert in into java.util.Date object as follows.

Date date = Date.from(addedDate.atStartOfDay(ZoneId.systemDefault()).toInstant());

You can formate LocalDate into a String as follows.

String str = addedDate.format(DateTimeFormatter.ofPattern("yyyy-MM-dd"));

Take a look at Joda-Time (https://www.joda.org/joda-time/).

DateTimeFormatter parser = ISODateTimeFormat.date();

DateTime date = parser.parseDateTime(dateString);

String nextDay = parser.print(date.plusDays(1));

You can use this package from "org.apache.commons.lang3.time":

 SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
 Date myNewDate = DateUtils.addDays(myDate, 4);
 Date yesterday = DateUtils.addDays(myDate, -1);
 String formatedDate = sdf.format(myNewDate);  

java.time

On Java 8 and later, the java.time package makes this pretty much automatic. (Tutorial)

Assuming String input and output:

import java.time.LocalDate;

public class DateIncrementer {
  static public String addOneDay(String date) {
    return LocalDate.parse(date).plusDays(1).toString();
  }
}

With Java SE 8 or higher you should use the new Date/Time API

 int days = 7;       
 LocalDate dateRedeemed = LocalDate.now();
 DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd/MM/YYYY");

 String newDate = dateRedeemed.plusDays(days).format(formatter);   
 System.out.println(newDate);

If you need to convert from java.util.Date to java.time.LocalDate, you may use this method.

  public LocalDate asLocalDate(Date date) {
      Instant instant = date.toInstant();
      ZonedDateTime zdt = instant.atZone(ZoneId.systemDefault());
      return zdt.toLocalDate();
  }

With a version prior to Java SE 8 you may use Joda-Time

Joda-Time provides a quality replacement for the Java date and time classes and is the de facto standard date and time library for Java prior to Java SE 8

   int days = 7;       
   DateTime dateRedeemed = DateTime.now();
   DateTimeFormatter formatter = DateTimeFormat.forPattern("dd/MM/uuuu");
        
   String newDate = dateRedeemed.plusDays(days).toString(formatter);   
   System.out.println(newDate);

SimpleDateFormat dateFormat = new SimpleDateFormat( "yyyy-MM-dd" );
Calendar cal = Calendar.getInstance();
cal.setTime( dateFormat.parse( inputString ) );
cal.add( Calendar.DATE, 1 );

In Java 8 simple way to do is:

Date.from(Instant.now().plusSeconds(SECONDS_PER_DAY))

Use the DateFormat API to convert the String into a Date object, then use the Calendar API to add one day. Let me know if you want specific code examples, and I can update my answer.

Something like this should do the trick:

String dt = "2008-01-01";  // Start date
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar c = Calendar.getInstance();
c.setTime(sdf.parse(dt));
c.add(Calendar.DATE, 1);  // number of days to add
dt = sdf.format(c.getTime());  // dt is now the new date

Date today = new Date();               
SimpleDateFormat formattedDate = new SimpleDateFormat("yyyyMMdd");            
Calendar c = Calendar.getInstance();        
c.add(Calendar.DATE, 1);  // number of days to add      
String tomorrow = (String)(formattedDate.format(c.getTime()));
System.out.println("Tomorrows date is " + tomorrow);

This will give tomorrow's date. c.add(...) parameters could be changed from 1 to another number for appropriate increment.

Construct a Calendar object and use the method add(Calendar.DATE, 1);

In Java 8 simple way to do is:

Date.from(Instant.now().plusSeconds(SECONDS_PER_DAY))

If you are using Java 8, then do it like this.

LocalDate sourceDate = LocalDate.of(2017, Month.MAY, 27);  // Source Date
LocalDate destDate = sourceDate.plusDays(1); // Adding a day to source date.

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd"); // Setting date format

String destDate = destDate.format(formatter));  // End date

If you want to use SimpleDateFormat, then do it like this.

String sourceDate = "2017-05-27";  // Start date

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

Calendar calendar = Calendar.getInstance();
calendar.setTime(sdf.parse(sourceDate)); // parsed date and setting to calendar

calendar.add(Calendar.DATE, 1);  // number of days to add
String destDate = sdf.format(calendar.getTime());  // End date

SimpleDateFormat dateFormat = new SimpleDateFormat( "yyyy-MM-dd" );
Calendar cal = Calendar.getInstance();
cal.setTime( dateFormat.parse( inputString ) );
cal.add( Calendar.DATE, 1 );

Take a look at Joda-Time (https://www.joda.org/joda-time/).

DateTimeFormatter parser = ISODateTimeFormat.date();

DateTime date = parser.parseDateTime(dateString);

String nextDay = parser.print(date.plusDays(1));

Something like this should do the trick:

String dt = "2008-01-01";  // Start date
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar c = Calendar.getInstance();
c.setTime(sdf.parse(dt));
c.add(Calendar.DATE, 1);  // number of days to add
dt = sdf.format(c.getTime());  // dt is now the new date

Since Java 1.5 TimeUnit.DAYS.toMillis(1) looks more clean to me.

SimpleDateFormat dateFormat = new SimpleDateFormat( "yyyy-MM-dd" );
Date day = dateFormat.parse(string);
// add the day
Date dayAfter = new Date(day.getTime() + TimeUnit.DAYS.toMillis(1));

It's very simple, trying to explain in a simple word. get the today's date as below

Calendar calendar = Calendar.getInstance();
System.out.println(calendar.getTime());// print today's date
calendar.add(Calendar.DATE, 1);

Now set one day ahead with this date by calendar.add method which takes (constant, value). Here constant could be DATE, hours, min, sec etc. and value is the value of constant. Like for one day, ahead constant is Calendar.DATE and its value are 1 because we want one day ahead value.

System.out.println(calendar.getTime());// print modified date which is tomorrow's date

Thanks

If you want to add a single unit of time and you expect that other fields to be incremented as well, you can safely use add method. See example below:

SimpleDateFormat simpleDateFormat1 = new SimpleDateFormat("yyyy-MM-dd");
Calendar cal = Calendar.getInstance();
cal.set(1970,Calendar.DECEMBER,31);
System.out.println(simpleDateFormat1.format(cal.getTime()));
cal.add(Calendar.DATE, 1);
System.out.println(simpleDateFormat1.format(cal.getTime()));
cal.add(Calendar.DATE, -1);
System.out.println(simpleDateFormat1.format(cal.getTime()));

Will Print:

1970-12-31
1971-01-01
1970-12-31

Take a look at Joda-Time (https://www.joda.org/joda-time/).

DateTimeFormatter parser = ISODateTimeFormat.date();

DateTime date = parser.parseDateTime(dateString);

String nextDay = parser.print(date.plusDays(1));

SimpleDateFormat dateFormat = new SimpleDateFormat( "yyyy-MM-dd" );
Calendar cal = Calendar.getInstance();
cal.setTime( dateFormat.parse( inputString ) );
cal.add( Calendar.DATE, 1 );

Apache Commons already has this DateUtils.addDays(Date date, int amount) http://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/time/DateUtils.html#addDays%28java.util.Date,%20int%29 which you use or you could go with the JodaTime to make it more cleaner.

Just pass date in String and number of next days

 private String getNextDate(String givenDate,int noOfDays) {
        SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
        Calendar cal = Calendar.getInstance();
        String nextDaysDate = null;
    try {
        cal.setTime(dateFormat.parse(givenDate));
        cal.add(Calendar.DATE, noOfDays);

       nextDaysDate = dateFormat.format(cal.getTime());

    } catch (ParseException ex) {
        Logger.getLogger(GR_TravelRepublic.class.getName()).log(Level.SEVERE, null, ex);
    }finally{
    dateFormat = null;
    cal = null;
    }

    return nextDaysDate;

}

long timeadj = 24*60*60*1000;
Date newDate = new Date (oldDate.getTime ()+timeadj);

This takes the number of milliseconds since epoch from oldDate and adds 1 day worth of milliseconds then uses the Date() public constructor to create a date using the new value. This method allows you to add 1 day, or any number of hours/minutes, not only whole days.

Date newDate = new Date();
newDate.setDate(newDate.getDate()+1);
System.out.println(newDate);

Java does appear to be well behind the eight-ball compared to C#. This utility method shows the way to do in Java SE 6 using the Calendar.add method (presumably the only easy way).

public class DateUtil
{
    public static Date addDays(Date date, int days)
    {
        Calendar cal = Calendar.getInstance();
        cal.setTime(date);
        cal.add(Calendar.DATE, days); //minus number would decrement the days
        return cal.getTime();
    }
}

To add one day, per the question asked, call it as follows:

String sourceDate = "2012-02-29";
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
Date myDate = format.parse(sourceDate);
myDate = DateUtil.addDays(myDate, 1);

It's simple actually. One day contains 86400000 milliSeconds. So first you get the current time in millis from The System by usingSystem.currentTimeMillis() then add the 84000000 milliSeconds and use the Date Class to generate A date format for the milliseconds.

Example

String Today = new Date(System.currentTimeMillis()).toString();

String Today will be 2019-05-9

String Tommorow = new Date(System.currentTimeMillis() + 86400000).toString();

String Tommorow will be 2019-05-10

String DayAfterTommorow = new Date(System.currentTimeMillis() + (2 * 86400000)).toString();

String DayAfterTommorow will be 2019-05-11

In java 8 you can use java.time.LocalDate

LocalDate parsedDate = LocalDate.parse("2015-10-30"); //Parse date from String
LocalDate addedDate = parsedDate.plusDays(1);   //Add one to the day field

You can convert in into java.util.Date object as follows.

Date date = Date.from(addedDate.atStartOfDay(ZoneId.systemDefault()).toInstant());

You can formate LocalDate into a String as follows.

String str = addedDate.format(DateTimeFormatter.ofPattern("yyyy-MM-dd"));

Java 8 added a new API for working with dates and times.

With Java 8 you can use the following lines of code:

// parse date from yyyy-mm-dd pattern
LocalDate januaryFirst = LocalDate.parse("2014-01-01");

// add one day
LocalDate januarySecond = januaryFirst.plusDays(1);

Use the DateFormat API to convert the String into a Date object, then use the Calendar API to add one day. Let me know if you want specific code examples, and I can update my answer.

Something like this should do the trick:

String dt = "2008-01-01";  // Start date
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar c = Calendar.getInstance();
c.setTime(sdf.parse(dt));
c.add(Calendar.DATE, 1);  // number of days to add
dt = sdf.format(c.getTime());  // dt is now the new date

Use the DateFormat API to convert the String into a Date object, then use the Calendar API to add one day. Let me know if you want specific code examples, and I can update my answer.

If you are using Java 8, java.time.LocalDate and java.time.format.DateTimeFormatter can make this work quite simple.

public String nextDate(String date){
      LocalDate parsedDate = LocalDate.parse(date);
      LocalDate addedDate = parsedDate.plusDays(1);
      DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-mm-dd");
      return addedDate.format(formatter); 
}

long timeadj = 24*60*60*1000;
Date newDate = new Date (oldDate.getTime ()+timeadj);

This takes the number of milliseconds since epoch from oldDate and adds 1 day worth of milliseconds then uses the Date() public constructor to create a date using the new value. This method allows you to add 1 day, or any number of hours/minutes, not only whole days.

Use the DateFormat API to convert the String into a Date object, then use the Calendar API to add one day. Let me know if you want specific code examples, and I can update my answer.

If you are using Java 8, then do it like this.

LocalDate sourceDate = LocalDate.of(2017, Month.MAY, 27);  // Source Date
LocalDate destDate = sourceDate.plusDays(1); // Adding a day to source date.

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd"); // Setting date format

String destDate = destDate.format(formatter));  // End date

If you want to use SimpleDateFormat, then do it like this.

String sourceDate = "2017-05-27";  // Start date

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

Calendar calendar = Calendar.getInstance();
calendar.setTime(sdf.parse(sourceDate)); // parsed date and setting to calendar

calendar.add(Calendar.DATE, 1);  // number of days to add
String destDate = sdf.format(calendar.getTime());  // End date

Take a look at Joda-Time (https://www.joda.org/joda-time/).

DateTimeFormatter parser = ISODateTimeFormat.date();

DateTime date = parser.parseDateTime(dateString);

String nextDay = parser.print(date.plusDays(1));

you can use Simple java.util lib

Calendar cal = Calendar.getInstance(); 
cal.setTime(yourDate); 
cal.add(Calendar.DATE, 1);
yourDate = cal.getTime();

Apache Commons already has this DateUtils.addDays(Date date, int amount) http://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/time/DateUtils.html#addDays%28java.util.Date,%20int%29 which you use or you could go with the JodaTime to make it more cleaner.

Try this method:

public static Date addDay(int day) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTime(new Date());
        calendar.add(Calendar.DATE, day);
        return calendar.getTime();
}

Let's clarify the use case: You want to do calendar arithmetic and start/end with a java.util.Date.

Some approaches:

1. Convert to string and back with SimpleDateFormat: This is an inefficient solution.
2. Convert to LocalDate: You would lose any time-of-day information.
3. Convert to LocalDateTime: This involves more steps and you need to worry about timezone.
4. Convert to epoch with Date.getTime(): This is efficient but you are calculating with milliseconds.

Consider using java.time.Instant:

Date _now = new Date();
Instant _instant = _now.toInstant().minus(5, ChronoUnit.DAYS);
Date _newDate = Date.from(_instant);

startCalendar.add(Calendar.DATE, 1); //Add 1 Day to the current Calender

Java 8 added a new API for working with dates and times.

With Java 8 you can use the following lines of code:

// parse date from yyyy-mm-dd pattern
LocalDate januaryFirst = LocalDate.parse("2014-01-01");

// add one day
LocalDate januarySecond = januaryFirst.plusDays(1);

I prefer to use DateUtils from Apache. Check this http://commons.apache.org/proper/commons-lang/javadocs/api-2.6/org/apache/commons/lang/time/DateUtils.html. It is handy especially when you have to use it multiple places in your project and would not want to write your one liner method for this.

The API says:

addDays(Date date, int amount) : Adds a number of days to a date returning a new object.

Note that it returns a new Date object and does not make changes to the previous one itself.

Construct a Calendar object and use the method add(Calendar.DATE, 1);

you can use Simple java.util lib

Calendar cal = Calendar.getInstance(); 
cal.setTime(yourDate); 
cal.add(Calendar.DATE, 1);
yourDate = cal.getTime();

Let's clarify the use case: You want to do calendar arithmetic and start/end with a java.util.Date.

Some approaches:

1. Convert to string and back with SimpleDateFormat: This is an inefficient solution.
2. Convert to LocalDate: You would lose any time-of-day information.
3. Convert to LocalDateTime: This involves more steps and you need to worry about timezone.
4. Convert to epoch with Date.getTime(): This is efficient but you are calculating with milliseconds.

Consider using java.time.Instant:

Date _now = new Date();
Instant _instant = _now.toInstant().minus(5, ChronoUnit.DAYS);
Date _newDate = Date.from(_instant);

startCalendar.add(Calendar.DATE, 1); //Add 1 Day to the current Calender

Please note that this line adds 24 hours:

d1.getTime() + 1 * 24 * 60 * 60 * 1000

but this line adds one day

cal.add( Calendar.DATE, 1 );

On days with a daylight savings time change (25 or 23 hours) you will get different results!

Something like this should do the trick:

String dt = "2008-01-01";  // Start date
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar c = Calendar.getInstance();
c.setTime(sdf.parse(dt));
c.add(Calendar.DATE, 1);  // number of days to add
dt = sdf.format(c.getTime());  // dt is now the new date

Since Java 1.5 TimeUnit.DAYS.toMillis(1) looks more clean to me.

SimpleDateFormat dateFormat = new SimpleDateFormat( "yyyy-MM-dd" );
Date day = dateFormat.parse(string);
// add the day
Date dayAfter = new Date(day.getTime() + TimeUnit.DAYS.toMillis(1));