Java – Add days to date

In this article, we will take a look at 2 different ways to add/subtract days, months or years from current date as well as any given date in java with examples.

1. LocalDate – Add days to current date
Java 8 LocalDate has a now() method which returns an object having current date.
To add days to this date, it has plusDays() method which accepts a long value representing the number of days to be added to this date. Example,

// get current date
LocalDate currentDate = LocalDate.now();
// add 30 days
LocalDate plusDays = currentDate.plusDays(30);
System.out.println("Current Date: " + currentDate);
System.out.println("Date after 30 days: " + plusDays);

Output is

LocalDate also provides methods to add months, weeks and years with plusMonths(), plusWeeks() and plusYears() methods respectively.
It also has corresponding methods to subtract these values from a date.

Remember that LocalDate is an immutable class. This means that all these methods return a new object rather than modifying the original object.
2. LocalDate – Add days to another date
Create a date using LocalDate.of() method.
of() takes year, month and date as arguments and returns a date with these values.

Use plusDays(), plusMonths(), plusWeeks() and plusYears() methods to add values to this date as shown above. Example,

LocalDate currentDate = LocalDate.of(2022, 1,1);
LocalDate plusDays = currentDate.plusMonths(2);
System.out.println("Current Date: " + currentDate);
System.out.println("Date after 2 months: " + plusDays);

Output is

3. Calendar – Add days to current date
java.util.Calendar object provides a generic add() method which accepts 2 arguments:
A. Date component that needs to be added or subtracted.
B. Number that will be added/subtracted.

To create a calendar object, use its static getInstance() method and to get the date encapsulated by this object, use its getTime() method.
Below code adds 7 days to current date.

// create calendar object
Calendar calendar = Calendar.getInstance();
System.out.println("Current date: " + calendar.getTime());
// add 7 days
calendar.add(Calendar.DATE, 7);
System.out.println("Date after 7 days: " + calendar.getTime());

Output is

To subtract a value from current date, provide a negative value to the second argument to add().
Note that getTime() internally creates a Date object using its constructor.
4. Calendar – Add days to other date
To create a date other than current date, java.util.Calendar object provides a set() method.
Using set(), we can set the value of a date component(such as day, month or year) to some other value.
Once the calendar is updated to a desired date, we can add days to it using add() method. Example,

Calendar calendar = Calendar.getInstance();
// set calendar to other date
calendar.set(Calendar.DATE, 31);
calendar.set(Calendar.MONTH, 11);
calendar.set(Calendar.YEAR, 2022);
System.out.println("Current date: " + calendar.getTime());
// add 1 day
calendar.add(Calendar.DATE, 1);
System.out.println("Date after 1 day: " + calendar.getTime());

Output is

Note that calendar counts the months starting from 0. So, a month set to 11 means December.
A value greater than 12 will set the month accordingly without raising any error.

Hope the article was useful.