leap-year-finder
leap-year-finder is a simple JavaScript library that provides functions for calculating leap years.
Install
$ npm install @gennyboy/leap-year-finder
Usage
To use the package, import the desired functions and call them with the appropriate arguments.
import { isLeapYear, getNextLeapYear } from "@gennyboy/leap-year-finder";
isLeapYear(2020); // true
getNextLeapYear(2020); // 2024API
isLeapYear(year)
Returns true if the given year is a leap year, false otherwise.
year
The year to check. If not specified, the current year is used.
Must be a number or a Date object.
isLeapYear(2020);
//=> true
isLeapYear(2021);
//=> false
isLeapYear(); // Check if the current year is a leap year or not.isCurrentYearLeap()
Returns true if the current year is a leap year, false otherwise.
// Executes in 2020
isCurrentYearLeap();
//=> true
// Executes in 2021
isCurrentYearLeap();
//=> falsegetNextLeapYear(year)
Returns the next leap year after the given year (or the current year if not specified).
year
The year to check. If not specified, the current year is used.
Must be a number or a Date object.
getNextLeapYear(2019);
//=> 2020
getNextLeapYear(2020);
//=> 2024
// Executes in 2019
getNextLeapYear();
//=> 2020getPreviousLeapYear(year)
Returns the previous leap year before the given year (or the current year if not specified).
year
The year to check. If not specified, the current year is used.
Must be a number or a Date object.
getPreviousLeapYear(2021);
//=> 2020
getPreviousLeapYear(2020);
//=> 2016
// Executes in 2021
getPreviousLeapYear();
//=> 2020getNextLeapYears(numberOfYears, year)
Returns an array of the next numberOfYears leap years after the given year (or the current year if not specified).
numberOfYears
The number of leap years to return.
Must be a number in range of 1 to 10.
year
The year to check. If not specified, the current year is used.
Must be a number or a Date object.
getNextLeapYears(3, 2020);
//=> [2024, 2028, 2032]
getNextLeapYears(3, 2019);
//=> [2020, 2024, 2028]
// Executes in 2019
getNextLeapYears(3);
//=> [2020, 2024, 2028]getPreviousLeapYears(numberOfYears, year)
Returns an array of the previous numberOfYears leap years before the given year (or the current year if not specified).
numberOfYears
The number of leap years to return.
Must be a number in range of 1 to 10.
year
The year to check. If not specified, the current year is used.
Must be a number or a Date object.
getPreviousLeapYears(3, 2020);
//=> [2016, 2012, 2008]
getPreviousLeapYears(3, 2021);
//=> [2020, 2016, 2012]
// Executes in 2021
getPreviousLeapYears(3);
//=> [2020, 2016, 2012]getDateForLastDayOfFebruary(year)
Returns the date object for the last day of February for the given year (or the current year if not specified).
year
The year to check. If not specified, the current year is used.
Must be a number or a Date object.
getDateForLastDayOfFebruary(2020);
//=> Sat Feb 29 2020 00:00:00 GMT+0900
getDateForLastDayOfFebruary(2021);
//=> Sun Feb 28 2021 00:00:00 GMT+0900
// Executes in 2021
getDateForLastDayOfFebruary();
//=> Sun Feb 28 2021 00:00:00 GMT+0900getDateForNextLeapYearLastDayOfFebruary()
Returns the date object for the last day of February for the next leap year.
// Executes in 2019
getDateForNextLeapYearLastDayOfFebruary();
//=> Sat Feb 29 2020 00:00:00 GMT+0900
// Executes in 2020
getDateForNextLeapYearLastDayOfFebruary();
//=> Sat Feb 29 2024 00:00:00 GMT+0900getDateForPreviousLeapYearLastDayOfFebruary()
Returns the date object for the last day of February for the previous leap year.
// Executes in 2021
getDateForPreviousLeapYearLastDayOfFebruary();
//=> Sun Feb 28 2020 00:00:00 GMT+0900
// Executes in 2020
getDateForPreviousLeapYearLastDayOfFebruary();
//=> Sun Feb 28 2016 00:00:00 GMT+0900