# tablepress/3.4/libraries/vendor/PhpSpreadsheet/Calculation/DateTimeExcel/YearFrac.php

TablePress – Tables in WordPress made easy, version 3.4. 133 lines.

- Page: https://pluginprobe.com/plugins/tablepress/3.4/code/libraries/vendor/PhpSpreadsheet/Calculation/DateTimeExcel/YearFrac.php
- Raw: https://pluginprobe.com/plugins/tablepress/3.4/raw/libraries/vendor/PhpSpreadsheet/Calculation/DateTimeExcel/YearFrac.php
- Modified: 2025-08-26T04:06:14+00:00

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```php
<?php

namespace TablePress\PhpOffice\PhpSpreadsheet\Calculation\DateTimeExcel;

use TablePress\PhpOffice\PhpSpreadsheet\Calculation\ArrayEnabled;
use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Exception;
use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Functions;
use TablePress\PhpOffice\PhpSpreadsheet\Calculation\Information\ExcelError;
use TablePress\PhpOffice\PhpSpreadsheet\Shared\Date as SharedDateHelper;

class YearFrac
{
	use ArrayEnabled;

	/**
	 * YEARFRAC.
	 *
	 * Calculates the fraction of the year represented by the number of whole days between two dates
	 * (the start_date and the end_date).
	 * Use the YEARFRAC worksheet function to identify the proportion of a whole year's benefits or
	 * obligations to assign to a specific term.
	 *
	 * Excel Function:
	 *        YEARFRAC(startDate,endDate[,method])
	 * See https://lists.oasis-open.org/archives/office-formula/200806/msg00039.html
	 *     for description of algorithm used in Excel
	 *
	 * @param mixed $startDate Excel date serial value (float), PHP date timestamp (integer),
	 *                                    PHP DateTime object, or a standard date string
	 *                         Or can be an array of values
	 * @param mixed $endDate Excel date serial value (float), PHP date timestamp (integer),
	 *                                    PHP DateTime object, or a standard date string
	 *                         Or can be an array of methods
	 * @param array<mixed>|int $method Method used for the calculation
	 *                                        0 or omitted    US (NASD) 30/360
	 *                                        1                Actual/actual
	 *                                        2                Actual/360
	 *                                        3                Actual/365
	 *                                        4                European 30/360
	 *                         Or can be an array of methods
	 *
	 * @return array<mixed>|float|int|string fraction of the year, or a string containing an error
	 *         If an array of values is passed for the $startDate or $endDays,arguments, then the returned result
	 *            will also be an array with matching dimensions
	 */
	public static function fraction($startDate, $endDate, $method = 0)
	{
		if (is_array($startDate) || is_array($endDate) || is_array($method)) {
			return self::evaluateArrayArguments([self::class, __FUNCTION__], $startDate, $endDate, $method);
		}

		try {
			$method = (int) Helpers::validateNumericNull($method);
			$sDate = Helpers::getDateValue($startDate);
			$eDate = Helpers::getDateValue($endDate);
			$sDate = self::excelBug($sDate, $startDate, $endDate, $method);
			$eDate = self::excelBug($eDate, $endDate, $startDate, $method);
			$startDate = min($sDate, $eDate);
			$endDate = max($sDate, $eDate);
		} catch (Exception $e) {
			return $e->getMessage();
		}

		switch ($method) {
									case 0:
										return Helpers::floatOrInt(Days360::between($startDate, $endDate)) / 360;
									case 1:
										return self::method1($startDate, $endDate);
									case 2:
										return Helpers::floatOrInt(Difference::interval($startDate, $endDate)) / 360;
									case 3:
										return Helpers::floatOrInt(Difference::interval($startDate, $endDate)) / 365;
									case 4:
										return Helpers::floatOrInt(Days360::between($startDate, $endDate, true)) / 360;
									default:
										return ExcelError::NAN();
								}
	}

	/**
				 * Excel 1900 calendar treats date argument of null as 1900-01-00. Really.
				 * @param mixed $startDate
				 * @param mixed $endDate
				 */
				private static function excelBug(float $sDate, $startDate, $endDate, int $method): float
	{
		if (Functions::getCompatibilityMode() !== Functions::COMPATIBILITY_OPENOFFICE && SharedDateHelper::getExcelCalendar() !== SharedDateHelper::CALENDAR_MAC_1904) {
			if ($endDate === null && $startDate !== null) {
				if (DateParts::month($sDate) == 12 && DateParts::day($sDate) === 31 && $method === 0) {
					$sDate += 2;
				} else {
					++$sDate;
				}
			}
		}

		return $sDate;
	}

	private static function method1(float $startDate, float $endDate): float
	{
		$days = Helpers::floatOrInt(Difference::interval($startDate, $endDate));
		$startYear = (int) DateParts::year($startDate);
		$endYear = (int) DateParts::year($endDate);
		$years = $endYear - $startYear + 1;
		$startMonth = (int) DateParts::month($startDate);
		$startDay = (int) DateParts::day($startDate);
		$endMonth = (int) DateParts::month($endDate);
		$endDay = (int) DateParts::day($endDate);
		$startMonthDay = 100 * $startMonth + $startDay;
		$endMonthDay = 100 * $endMonth + $endDay;
		if ($years == 1) {
			$tmpCalcAnnualBasis = 365 + (int) Helpers::isLeapYear($endYear);
		} elseif ($years == 2 && $startMonthDay >= $endMonthDay) {
			if (Helpers::isLeapYear($startYear)) {
				$tmpCalcAnnualBasis = 365 + (int) ($startMonthDay <= 229);
			} elseif (Helpers::isLeapYear($endYear)) {
				$tmpCalcAnnualBasis = 365 + (int) ($endMonthDay >= 229);
			} else {
				$tmpCalcAnnualBasis = 365;
			}
		} else {
			$tmpCalcAnnualBasis = 0;
			for ($year = $startYear; $year <= $endYear; ++$year) {
				$tmpCalcAnnualBasis += 365 + (int) Helpers::isLeapYear($year);
			}
			$tmpCalcAnnualBasis /= $years;
		}

		return $days / $tmpCalcAnnualBasis;
	}
}

```