diff options
| author | Pinapelz <yukais@pinapelz.com> | 2025-06-28 17:26:46 -0700 |
|---|---|---|
| committer | Pinapelz <yukais@pinapelz.com> | 2025-06-28 17:43:56 -0700 |
| commit | e4fa1e69e7ebfb627c7198fd1a9881e9327ec4d4 (patch) | |
| tree | 06284a538a6008eca75051399e47db4e5d50301c /node_modules/date-fns/esm/differenceInMonths/index.js | |
initial commit: scaffolding
Diffstat (limited to 'node_modules/date-fns/esm/differenceInMonths/index.js')
| -rw-r--r-- | node_modules/date-fns/esm/differenceInMonths/index.js | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/node_modules/date-fns/esm/differenceInMonths/index.js b/node_modules/date-fns/esm/differenceInMonths/index.js new file mode 100644 index 0000000..6635d07 --- /dev/null +++ b/node_modules/date-fns/esm/differenceInMonths/index.js @@ -0,0 +1,56 @@ +import toDate from "../toDate/index.js"; +import differenceInCalendarMonths from "../differenceInCalendarMonths/index.js"; +import compareAsc from "../compareAsc/index.js"; +import requiredArgs from "../_lib/requiredArgs/index.js"; +import isLastDayOfMonth from "../isLastDayOfMonth/index.js"; +/** + * @name differenceInMonths + * @category Month Helpers + * @summary Get the number of full months between the given dates. + * + * @description + * Get the number of full months between the given dates using trunc as a default rounding method. + * + * @param {Date|Number} dateLeft - the later date + * @param {Date|Number} dateRight - the earlier date + * @returns {Number} the number of full months + * @throws {TypeError} 2 arguments required + * + * @example + * // How many full months are between 31 January 2014 and 1 September 2014? + * const result = differenceInMonths(new Date(2014, 8, 1), new Date(2014, 0, 31)) + * //=> 7 + */ +export default function differenceInMonths(dirtyDateLeft, dirtyDateRight) { + requiredArgs(2, arguments); + var dateLeft = toDate(dirtyDateLeft); + var dateRight = toDate(dirtyDateRight); + var sign = compareAsc(dateLeft, dateRight); + var difference = Math.abs(differenceInCalendarMonths(dateLeft, dateRight)); + var result; + + // Check for the difference of less than month + if (difference < 1) { + result = 0; + } else { + if (dateLeft.getMonth() === 1 && dateLeft.getDate() > 27) { + // This will check if the date is end of Feb and assign a higher end of month date + // to compare it with Jan + dateLeft.setDate(30); + } + dateLeft.setMonth(dateLeft.getMonth() - sign * difference); + + // Math.abs(diff in full months - diff in calendar months) === 1 if last calendar month is not full + // If so, result must be decreased by 1 in absolute value + var isLastMonthNotFull = compareAsc(dateLeft, dateRight) === -sign; + + // Check for cases of one full calendar month + if (isLastDayOfMonth(toDate(dirtyDateLeft)) && difference === 1 && compareAsc(dirtyDateLeft, dateRight) === 1) { + isLastMonthNotFull = false; + } + result = sign * (difference - Number(isLastMonthNotFull)); + } + + // Prevent negative zero + return result === 0 ? 0 : result; +}
\ No newline at end of file |
