在PHP中执行与datetime相关的操作

Question

你如何实际执行日期时间操作,例如添加日期,找到差异,找出在一个时间间隔内排除周末的天数？我个人开始将这些操作中的一些传递给我的postgresql dbms,因为通常我只需要发出一个sql语句来获得答案,但是,用PHP方式来做这件事我将不得不写更多的代码意味着更多的机会发生错误......

PHP中是否有任何库以不需要大量代码的方式执行日期时间操作？在'给定两个日期,两个日期之间有多少个工作日？在SQL或$ pet_lang'中实现,通过进行此查询来解决？

SELECT  COUNT(*) AS total_days
FROM    (SELECT date '2008-8-26' + generate_series(0,
          (date '2008-9-1' - date '2008-8-26')) AS all_days) AS calendar
WHERE   EXTRACT(isodow FROM all_days) < 6;

Answer 1

对于大多数日期时间操作,我通常会转换为Unixtime并在Unixtime整数上执行加法减法等,您可能需要查看Zend框架Zend_Date类.

这有很多你描述的功能.虽然Zend被称为"框架",但它作为一个类库来挑选和选择元素非常好.我们经常将它包含在项目中,然后在我们需要它们时立即引入它们.

Answer 2

PHP5+ 的 DateTime 对象很有用，因为它可以识别闰年和夏令时，但它需要一些扩展才能真正解决问题。我写了以下内容来解决类似的问题。find_WeekdaysFromThisTo() 方法是强力方法，但如果您的时间跨度小于 2 年，它的工作速度相当快。

$tryme = new Extended_DateTime('2007-8-26');
$newer = new Extended_DateTime('2008-9-1');

print 'Weekdays From '.$tryme->format('Y-m-d').' To '.$newer->format('Y-m-d').': '.$tryme -> find_WeekdaysFromThisTo($newer) ."\n";
/*  Output:  Weekdays From 2007-08-26 To 2008-09-01: 265  */
print 'All Days From '.$tryme->format('Y-m-d').' To '.$newer->format('Y-m-d').': '.$tryme -> find_AllDaysFromThisTo($newer) ."\n";
/*  Output:  All Days From 2007-08-26 To 2008-09-01: 371   */
$timefrom = $tryme->find_TimeFromThisTo($newer);
print 'Between '.$tryme->format('Y-m-d').' and '.$newer->format('Y-m-d').' there are '.
      $timefrom['years'].' years, '.$timefrom['months'].' months, and '.$timefrom['days'].
      ' days.'."\n";
/*  Output: Between 2007-08-26 and 2008-09-01 there are 1 years, 0 months, and 5 days. */

class Extended_DateTime extends DateTime {

    public function find_TimeFromThisTo($newer) {
        $timefrom = array('years'=>0,'months'=>0,'days'=>0);

        // Clone because we're using modify(), which will destroy the object that was passed in by reference
        $testnewer = clone $newer;

        $timefrom['years'] = $this->find_YearsFromThisTo($testnewer);
        $mod = '-'.$timefrom['years'].' years';
        $testnewer -> modify($mod);

        $timefrom['months'] = $this->find_MonthsFromThisTo($testnewer);
        $mod = '-'.$timefrom['months'].' months';
        $testnewer -> modify($mod);

        $timefrom['days'] = $this->find_AllDaysFromThisTo($testnewer);
        return $timefrom;
    } // end function find_TimeFromThisTo


    public function find_YearsFromThisTo($newer) {
        /*
        If the passed is:
        not an object, not of class DateTime or one of its children,
        or not larger (after) $this
        return false
        */
        if (!is_object($newer) || !($newer instanceof DateTime) || $newer->format('U') < $this->format('U'))
            return FALSE;
        $count = 0;

        // Clone because we're using modify(), which will destroy the object that was passed in by reference
        $testnewer = clone $newer;

        $testnewer -> modify ('-1 year');
        while ( $this->format('U') < $testnewer->format('U')) {
            $count ++;
            $testnewer -> modify ('-1 year');
        }
        return $count;
    } // end function find_YearsFromThisTo


    public function find_MonthsFromThisTo($newer) {
        /*
        If the passed is:
        not an object, not of class DateTime or one of its children,
        or not larger (after) $this
        return false
        */
        if (!is_object($newer) || !($newer instanceof DateTime) || $newer->format('U') < $this->format('U'))
            return FALSE;

        $count = 0;
        // Clone because we're using modify(), which will destroy the object that was passed in by reference
        $testnewer = clone $newer;
        $testnewer -> modify ('-1 month');

        while ( $this->format('U') < $testnewer->format('U')) {
            $count ++;
            $testnewer -> modify ('-1 month');
        }
        return $count;
    } // end function find_MonthsFromThisTo


    public function find_AllDaysFromThisTo($newer) {
        /*
        If the passed is:
        not an object, not of class DateTime or one of its children,
        or not larger (after) $this
        return false
        */
        if (!is_object($newer) || !($newer instanceof DateTime) || $newer->format('U') < $this->format('U'))
            return FALSE;

        $count = 0;
        // Clone because we're using modify(), which will destroy the object that was passed in by reference
        $testnewer = clone $newer;
        $testnewer -> modify ('-1 day');

        while ( $this->format('U') < $testnewer->format('U')) {
            $count ++;
            $testnewer -> modify ('-1 day');
        }
        return $count;
    } // end function find_AllDaysFromThisTo


    public function find_WeekdaysFromThisTo($newer) {
        /*
        If the passed is:
        not an object, not of class DateTime or one of its children,
        or not larger (after) $this
        return false
        */
        if (!is_object($newer) || !($newer instanceof DateTime) || $newer->format('U') < $this->format('U'))
            return FALSE;

        $count = 0;

        // Clone because we're using modify(), which will destroy the object that was passed in by reference
        $testnewer = clone $newer;
        $testnewer -> modify ('-1 day');

        while ( $this->format('U') < $testnewer->format('U')) {
            // If the calculated day is not Sunday or Saturday, count this day
            if ($testnewer->format('w') != '0' && $testnewer->format('w') != '6')
                $count ++;
            $testnewer -> modify ('-1 day');
        }
        return $count;
    } // end function find_WeekdaysFromThisTo

    public function set_Day($newday) {
        if (is_int($newday) && $newday > 0 && $newday < 32 && checkdate($this->format('m'),$newday,$this->format('Y')))
            $this->setDate($this->format('Y'),$this->format('m'),$newday);
    } // end function set_Day


    public function set_Month($newmonth) {
        if (is_int($newmonth) && $newmonth > 0 && $newmonth < 13)
            $this->setDate($this->format('Y'),$newmonth,$this->format('d'));
    } // end function set_Month


    public function set_Year($newyear) {
        if (is_int($newyear) && $newyear > 0)
            $this->setDate($newyear,$this->format('m'),$this->format('d'));
    } // end function set_Year
} // end class Extended_DateTime