/**
* Represents a javascript class for calculating the difference between two dates in formatted ways like (aY bM cD)(aYears bMonths cDays) or customized desired formats like aY-bM-cD or aYears-bMonths-cDays or nDays or mWeeks etc.
*
* @class
*/
class DatesYMD {
/**
* Creates an instance of DatesYMD.
*
* @constructor
* @param {string} firstDate (type- String but Number for epoch, and Object for dateObject) - The first date in the format 'yyyy-mm-dd' or 'yyyy/mm/dd' or yyyy.mm.dd or dateString or dateObject
or Timestamp(epoch).
* @param {string} secondDate (type- String but Number for epoch, and Object for dateObject) - The second date in the format 'yyyy-mm-dd' or 'yyyy/mm/dd' or yyyy.mm.dd or dateString or dateObject
or Timestamp(epoch).
*/
constructor(firstDate, secondDate) {
this.firstDate = firstDate;
this.secondDate = secondDate;
// Handle empty date inputs by defaulting to the current date
this.handleEmpty = function () {
let firstD, secondD;
if (this.firstDate === '' && this.secondDate === '') {
firstD = new Date();
secondD = new Date();
} else if (this.firstDate === '') {
firstD = new Date();
secondD = new Date(this.secondDate);
} else if (this.secondDate === '') {
firstD = new Date(this.firstDate);
secondD = new Date();
} else {
firstD = new Date(this.firstDate);
secondD = new Date(this.secondDate);
}
return [firstD, secondD];
};
// Swap dates if the first date is smaller than the second date
this.swapDates = function (firstD, secondD) {
if (firstD.getTime() < secondD.getTime()) {
let negativeHandle = firstD;
firstD = secondD;
secondD = negativeHandle;
}
return [firstD, secondD];
};
// initializing dates difference
this.initDiff = function () {
let firstD, secondD, dates, swapped;
// Handle empty date inputs by defaulting to the current date
dates = this.handleEmpty();
(firstD = dates[0]), (secondD = dates[1]);
// Swap dates if the first date is smaller than the second date
swapped = this.swapDates(firstD, secondD);
if (swapped) {
(firstD = swapped[0]), (secondD = swapped[1]);
}
return [firstD, secondD];
};
}
/**
* Calculates the difference between two dates and returns an array containing Y, M, D, and a formatted 'aY bM cD' difference string.
*
* @method
* @returns {Array} An array containing the calculated years, months, days, and the formatted difference.
*/
diffArray() {
let year, month, day, monthAdjuster;
let firstD, secondD, dates, yearS, yearF, monthS, monthF, dateS, dateF, datesDiff;
// initializing dates difference
dates = this.initDiff();
(firstD = dates[0]), (secondD = dates[1]);
// Extract year, month, and date components of the two dates
yearS = secondD.getFullYear();
yearF = firstD.getFullYear();
monthS = secondD.getMonth() + 1;
monthF = firstD.getMonth() + 1;
dateS = secondD.getDate();
dateF = firstD.getDate();
// Calculate the difference in years, months, and days
if (monthF >= monthS && dateF >= dateS) {
year = yearF - yearS;
month = monthF - monthS;
day = dateF - dateS;
} else if (monthF < monthS && dateF >= dateS) {
// Handle the case where the months are different, and the first date's day is greater than or equal to the second date's day
day = dateF - dateS;
month = monthF + 12 - monthS;
year = yearF - 1 - yearS;
} else if (monthF > monthS && dateF < dateS) {
// Handle the case where the months are different, and the first date's day is less than the second date's day
month = monthF - monthS - 1;
year = yearF - yearS;
// Save the first last month of monthF for correct aY bM cD following mathematical finding algorithm for calculating aY bM cD correctly like if 2020-05-22 to 2021-03-20, then firstly decide monthAdjuster which is (greaterDate month - 1), that is 03 - 1 = 02, then find month from 20-05 to 21-02(02 is monthAdjuster) i.e 9M, and then decide days from 2021-02-22 to 2021-03-20
monthAdjuster = monthF - 1; // for getting intuitively correct - aY bM cD in all cases
// Further adjustments based on specific conditions
if (monthAdjuster === 2) {
// Handle February
if (yearF % 4 === 0) {
// Leap year logic
day = dateF > 29 ? dateF : 29 - dateS + dateF;
} else {
// Non-leap year logic
day = dateF > 28 ? dateF : 28 - dateS + dateF;
}
} else if (
// handle 30 days months
monthAdjuster === 4 ||
monthAdjuster === 6 ||
monthAdjuster === 8 ||
monthAdjuster === 11
) {
// Handle months with 30 days
day = dateF > 30 ? dateF : 30 - dateS + dateF;
} else {
// Handle months with 31 days
day = 31 - dateS + dateF;
}
} else if (monthF <= monthS && dateF < dateS) {
// Handle the case where the months are either different or equal, and the first date's day is less than the second date's day
month = monthF + 11 - monthS;
year = yearF - 1 - yearS;
monthAdjuster = monthF - 1; // for getting intuitively correct - aY bM cD
// Further adjustments based on specific conditions
if (monthAdjuster === 2) {
// Handle February
if (yearF % 4 === 0) {
// Leap year logic
day = dateF > 29 ? dateF : 29 - dateS + dateF;
} else {
// Non-leap year logic
day = dateF > 28 ? dateF : 28 - dateS + dateF;
}
} else if (
// handle 30 days months
monthAdjuster === 4 ||
monthAdjuster === 6 ||
monthAdjuster === 8 ||
monthAdjuster === 11
) {
// Handle months with 30 days
day = dateF > 30 ? dateF : 30 - dateS + dateF;
} else {
// Handle months with 31 days
day = 31 - dateS + dateF;
}
}
// Format the difference and return the result
const diffFormat = year + 'Y ' + month + 'M ' + day + 'D';
datesDiff = [year, month, day, diffFormat];
return datesDiff;
}
/**
* Returns the formatted difference between two dates.
*
* @method
* @returns {string} The formatted difference in the format 'aY bM cD'.
*/
formattedYMD() {
return this.diffArray()[3];
}
/**
* Customizes the difference using specified units and separators like (a + yearUnit + partSeparator + b + monthUnit + partSeparator + c + dayUnit), eg. aYs-bMs-cDs etc.
*
* @method
* @param {string} yearUnit - The unit for years.
* @param {string} monthUnit - The unit for months.
* @param {string} dayUnit - The unit for days.
* @param {string} partSeparator - The separator between year, month, and day parts.
* @returns {string} The customized formatted difference.
*/
customizeFormat(yearUnit, monthUnit, dayUnit, partSeparator) {
let Y, M, D;
Y = this.diffArray()[0];
M = this.diffArray()[1];
D = this.diffArray()[2];
const customized =
Y +
yearUnit +
partSeparator +
M +
monthUnit +
partSeparator +
D +
dayUnit;
return customized;
}
/**
* Calculates the difference in months between two dates.
*
* @method
* @returns {number} The difference in months.
*/
diffInMonths() {
let ymdArray, year, month;
// initializing dates difference
ymdArray = this.diffArray();
// Extract year, month, and date components of the difference
(year = ymdArray[0]), (month = ymdArray[1]);
// calculate months
const months = year * 12 + month;
return months;
}
/**
* Calculates the difference in weeks between two dates.
*
* @method
* @returns {number} The difference in weeks.
*/
diffInWeeks() {
let dates, firstD, secondD;
// initializing dates difference
dates = this.initDiff();
(firstD = dates[0]), (secondD = dates[1]);
// calculate weeks
const weeks = Math.floor(
(firstD.getTime() - secondD.getTime()) / (7 * 24 * 60 * 60 * 1000),
);
return weeks;
}
/**
* Calculates the difference in days between two dates.
*
* @method
* @returns {number} The difference in days.
*/
diffInDays() {
let dates, firstD, secondD;
// initializing dates difference
dates = this.initDiff();
(firstD = dates[0]), (secondD = dates[1]);
// calculate days
const days = Math.floor(
(firstD.getTime() - secondD.getTime()) / (24 * 60 * 60 * 1000),
);
return days;
}
/**
* Calculates the difference in years between two dates.
*
* @method
* @returns {number} The difference in years.
*/
diffInYears() {
let ymdArray;
// get dates difference array
ymdArray = this.diffArray();
// Extract year component of the difference
const years = ymdArray[0];
return years;
}
/**
* Calculates the difference in hours between two dates.
*
* @method
* @returns {number} The difference in hours.
*/
diffInHours() {
let days, hours;
// get dates difference days
days = this.diffInDays();
// calculate hours
hours = days * 24;
return hours;
}
/**
* Calculates the difference in minutes between two dates.
*
* @method
* @returns {number} The difference in minutes.
*/
diffInMinutes() {
let minutes, hours;
// get dates difference hours
hours = this.diffInHours();
// calculate minutes
minutes = hours * 60;
return minutes;
}
/**
* Calculates the difference in seconds between two dates.
*
* @method
* @returns {number} The difference in seconds.
*/
diffInSeconds() {
let seconds, minutes;
// get dates difference minutes
minutes = this.diffInMinutes();
// calculate seconds
seconds = minutes * 60;
return seconds;
}
}
// Export the DatesYMD class for usages in other modules
module.exports = DatesYMD;