See the date is a given day in the month.

@param string $date
@param int    $day
180402
public function seeDayInMonth($date, $day) {
        \PHPUnit_Framework_Assert::assertEquals($day, $this->_ParseDate($date)->day);
    }
457031
public function seeDayInWeek($date, $day) {
        \PHPUnit_Framework_Assert::assertEquals($day, $this->_ParseDate($date)->dayOfWeek);
    }
884023
public function seeDateIsMonday($date) {
        \PHPUnit_Framework_Assert::assertTrue($this->_ParseDate($date)->dayOfWeek == Carbon::MONDAY);
    }
1111941
public function setDate($year, $month, $day)
    {
        if($this->_date->setDate($year, $month, $day) === false) {
            return false;
        }

        return $this;
    }
1194834
protected static function checkDate($day, $month, $year)
    {
        // Tolerate both day-month and month-day order
        if ((12 <= $month && $month <= 31) && $day <= 12) {
            $m = $month;
            $month = $day;
            $day = $m;
        }
        if ($day > 31 || $month > 12) {
            return false;
        }
        if (!(1900 <= $year && $year <= 2019)) {
            return false;
        }

        return [$day, $month, $year];
    }
154885
function setDay(date, day) {
		// we don't want to change month when changing date
		var month = date.getMonth(),
			diff = day - (date.getDay() || 7);
		// move to correct date
		date.setDate(date.getDate() + diff);
		// check month
		if (date.getMonth() != month) {
			if (diff > 0) {
				date.setDate(date.getDate() - 7);
			} else {
				date.setDate(date.getDate() + 7);
			}
		}
	}
582944
public void setDate(Date date) {
		Date oldDate = calendar.getTime();
		calendar.setTime(date);
		int year = calendar.get(Calendar.YEAR);
		int month = calendar.get(Calendar.MONTH);
		int day = calendar.get(Calendar.DAY_OF_MONTH);

		yearChooser.setYear(year);
		monthChooser.setMonth(month);
		dayChooser.setCalendar(calendar);
		dayChooser.setDay(day);

		firePropertyChange("date", oldDate, date);
	}
1269041
public function setExpiresOn($date)
    {
        $date = AnDomainAttributeDate::getInstance()->setDate($date);
        $this->set('expiresOn', $date);
    }
762189
public static function date($date){

		$Date = static::_utcZeroDateTime($date);

		if($Date === null){

			return $date;
		}

		return $Date->format('Y-m-d');
	}
369669
private function parseDate($date): AbstractCalendarDate
    {
        // Valid calendar escape specified? - use it
        if (preg_match('/^(@#D(?:GREGORIAN|JULIAN|HEBREW|HIJRI|JALALI|FRENCH R|ROMAN)+@) ?(.*)/', $date, $match)) {
            $cal  = $match[1];
            $date = $match[2];
        } else {
            $cal = '';
        }
        // A date with a month: DM, M, MY or DMY
        if (preg_match('/^(\d?\d?) ?(JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC|TSH|CSH|KSL|TVT|SHV|ADR|ADS|NSN|IYR|SVN|TMZ|AAV|ELL|VEND|BRUM|FRIM|NIVO|PLUV|VENT|GERM|FLOR|PRAI|MESS|THER|FRUC|COMP|MUHAR|SAFAR|RABI[AT]|JUMA[AT]|RAJAB|SHAAB|RAMAD|SHAWW|DHUAQ|DHUAH|FARVA|ORDIB|KHORD|TIR|MORDA|SHAHR|MEHR|ABAN|AZAR|DEY|BAHMA|ESFAN) ?((?:\d{1,4}(?: B\.C\.)?|\d\d\d\d\/\d\d)?)$/', $date, $match)) {
            $d = $match[1];
            $m = $match[2];
            $y = $match[3];
        } elseif (preg_match('/^(\d{1,4}(?: B\.C\.)?|\d\d\d\d\/\d\d)$/', $date, $match)) {
            // A date with just a year
            $d = '';
            $m = '';
            $y = $match[1];
        } else {
            // An invalid date - do the best we can.
            $d = '';
            $m = '';
            $y = '';
            // Look for a 3/4 digit year anywhere in the date
            if (preg_match('/\b(\d{3,4})\b/', $date, $match)) {
                $y = $match[1];
            }
            // Look for a month anywhere in the date
            if (preg_match('/(JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC|TSH|CSH|KSL|TVT|SHV|ADR|ADS|NSN|IYR|SVN|TMZ|AAV|ELL|VEND|BRUM|FRIM|NIVO|PLUV|VENT|GERM|FLOR|PRAI|MESS|THER|FRUC|COMP|MUHAR|SAFAR|RABI[AT]|JUMA[AT]|RAJAB|SHAAB|RAMAD|SHAWW|DHUAQ|DHUAH|FARVA|ORDIB|KHORD|TIR|MORDA|SHAHR|MEHR|ABAN|AZAR|DEY|BAHMA|ESFAN)/', $date, $match)) {
                $m = $match[1];
                // Look for a day number anywhere in the date
                if (preg_match('/\b(\d\d?)\b/', $date, $match)) {
                    $d = $match[1];
                }
            }
        }

        // Unambiguous dates - override calendar escape
        if (preg_match('/^(TSH|CSH|KSL|TVT|SHV|ADR|ADS|NSN|IYR|SVN|TMZ|AAV|ELL)$/', $m)) {
            $cal = JewishDate::ESCAPE;
        } elseif (preg_match('/^(VEND|BRUM|FRIM|NIVO|PLUV|VENT|GERM|FLOR|PRAI|MESS|THER|FRUC|COMP)$/', $m)) {
            $cal = FrenchDate::ESCAPE;
        } elseif (preg_match('/^(MUHAR|SAFAR|RABI[AT]|JUMA[AT]|RAJAB|SHAAB|RAMAD|SHAWW|DHUAQ|DHUAH)$/', $m)) {
            $cal = HijriDate::ESCAPE; // This is a WT extension
        } elseif (preg_match('/^(FARVA|ORDIB|KHORD|TIR|MORDA|SHAHR|MEHR|ABAN|AZAR|DEY|BAHMA|ESFAN)$/', $m)) {
            $cal = JalaliDate::ESCAPE; // This is a WT extension
        } elseif (preg_match('/^\d{1,4}( B\.C\.)|\d\d\d\d\/\d\d$/', $y)) {
            $cal = JulianDate::ESCAPE;
        }

        // Ambiguous dates - don't override calendar escape
        if ($cal === '') {
            if (preg_match('/^(JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)$/', $m)) {
                $cal =  GregorianDate::ESCAPE;
            } elseif (preg_match('/^[345]\d\d\d$/', $y)) {
                // Year 3000-5999
                $cal = JewishDate::ESCAPE;
            } else {
                $cal = GregorianDate::ESCAPE;
            }
        }
        // Now construct an object of the correct type
        switch ($cal) {
            case GregorianDate::ESCAPE:
                return new GregorianDate([
                    $y,
                    $m,
                    $d,
                ]);
            case JulianDate::ESCAPE:
                return new JulianDate([
                    $y,
                    $m,
                    $d,
                ]);
            case JewishDate::ESCAPE:
                return new JewishDate([
                    $y,
                    $m,
                    $d,
                ]);
            case HijriDate::ESCAPE:
                return new HijriDate([
                    $y,
                    $m,
                    $d,
                ]);
            case FrenchDate::ESCAPE:
                return new FrenchDate([
                    $y,
                    $m,
                    $d,
                ]);
            case JalaliDate::ESCAPE:
                return new JalaliDate([
                    $y,
                    $m,
                    $d,
                ]);
            case RomanDate::ESCAPE:
                return new RomanDate([
                    $y,
                    $m,
                    $d,
                ]);
            default:
                throw new DomainException('Invalid calendar');
        }
    }
457328
public function seeDateIsFriday($date) {
        \PHPUnit_Framework_Assert::assertTrue($this->_ParseDate($date)->dayOfWeek == Carbon::FRIDAY);
    }
170727
public function containsDate($date): bool
    {
        $date = Date::castFrom($date);
        if (!$this->start->isBefore($date) && !$this->start->equals($date)) {
            return false;
        }

        if (!$this->end->isAfter($date) && !$this->end->equals($date)) {
            return false;
        }

        return true;
    }
1025292
private static int getDayOfMonth(Date date) {
		Calendar cal = Calendar.getInstance();
		cal.setTime(date);
		return cal.get(Calendar.DAY_OF_MONTH);
	}
460290
public static function addDays($date, $days) {
        if (Validator::isDateTime($date) === false) throw new InvalidArgumentException('Invalid argument $date: '.$date);
        if (!is_int($days))                         throw new IllegalTypeException('Illegal type of parameter $days: '.gettype($days));

        $parts = explode('-', $date);
        $year  = (int) $parts[0];
        $month = (int) $parts[1];
        $day   = (int) $parts[2];

        return date('Y-m-d', mktime(0, 0, 0, $month, $day+$days, $year));
    }
958416
public function setDate($date)
    {
        if (!is_numeric($date))
        {
            $date = strtotime($date);
        }

        if ($this->version == Eresus_Feed_Writer::ATOM)
        {
            $tag = 'updated';
            $value = date(DATE_ATOM, $date);
        }
        elseif ($this->version == Eresus_Feed_Writer::RSS2)
        {
            $tag = 'pubDate';
            $value = date(DATE_RSS, $date);
        }
        else
        {
            $tag = 'dc:date';
            $value = date("Y-m-d", $date);
        }

        $this->addElement($tag, $value);
    }
196842
public final function setDay( int $day = null )
      : DateTime
   {

      if ( \is_null( $day ) )
      {
         $day = static::CurrentDay();
      }

      return $this->setDateParts( null, null, $day );

   }
456980
public function setDate(\DateTime $date): void
    {
        $this->getFileElement()->setAttributeNS(static::XLIFF_NS, 'date', $date->format(\DateTime::ATOM));
    }