Altera o timestamp com modificados textual
Ex:. +1 month

@param type $modify
@return type
549356
public function dateModify($modify) {
        $modified = (array) $this->dateTime->modify($modify);
        $date = explode(' ', $modified['date']);

        return $this->setDate($date[0])->parseDate();
    }
1107013
public function modify($input)
    {
        foreach ($this->getModifiers() as $modifier) {
            $input = $modifier->modify($input);
        }

        return $input;
    }
482273
private function modify()
	{
		// Add any automatic fields
		$this->parseAutomatics('renew');
		$data = $this->getTableColumnsOnly();
		// Return the result of the query
		return $this->query->alter(
			$this->getTableName(),
			$this->getPrimaryKey(),
			$this->getPkValue(),
			$data
		);
	}
628496
public function setModified(\DateTime $modified = null)
    {
        $this->_modified = null === $modified ? new \DateTime() : $modified;

        return $this->getContentInstance();
    }
752321
protected function modifyWeeks($amount, $invert = false)
        {
            $interval = new \DateInterval("P{$amount}W");

            $this->modifyFromInterval($interval, $invert);

            return $this;
        }
751370
public final function last(int $timeStamp = null): string
   {
       if ($timeStamp) {
           $this->lastModification = gmdate(
               "D, d M Y H:i:s",
               $timeStamp) . " GMT";
       }
       return $this->lastModification;
   }
534115
public function withDateAtEndOfMonth() : self
    {
        $instance = $this->withDateAtStartOfMonth();
        
        $instance->date->modify('+1 month');
        $instance->date->modify('-1 day');
        
        return $instance;
    }
103549
public function addMonths($value) {
        
        $monthToSet = (int) $this->month + $value;
        
        return $this->setDate($this->year, $monthToSet, $this->day);
    }
642713
public function plusMonths(int $months) : YearMonth
    {
        if ($months === 0) {
            return $this;
        }

        $month = $this->month + $months - 1;

        $yearDiff = Math::floorDiv($month, 12);
        $month = Math::floorMod($month, 12) + 1;

        $year = $this->year + $yearDiff;

        return new YearMonth($year, $month);
    }
390465
public static function createFromDateString($duration): self
    {
        $duration = parent::createFromDateString($duration);
        if (false === $duration) {
            return $duration;
        }

        $new = new self('PT0S');
        foreach ($duration as $name => $value) {
            $new->$name = $value;
        }

        return $new;
    }
889941
public function modify($change)
    {
        $date = clone $this;
        $date->setDate(strtotime($change, $this->getDate(DATE_FORMAT_UNIXTIME)));

        return $date;
    }
270109
public function set_timestamp($ts = null)
    {
        if (!is_numeric($ts)) {
            $this->time = null;
            $this->adate = null;
            return $this;
        }
        
        $old_year = ($this->time == null) ? false : $this->adate['year'];
        
        $this->time = $ts;
        $this->adate = getdate($ts);
        
        $this->adate['daysInMonth'] = date('t', $ts);
        
        //Test si on doit recalculer les jours fériés
        if ($old_year === false || $old_year != $this->adate['year']) {
            $this->set_joursferies($this->adate['year']);
        }
        
        return $this;
    }
91614
public function prev($offset = 1)
    {
        $prevDateTime = clone $this->startDateTime;
        $prevDateTime->modify('-'.abs($offset).' months');
        return new Month($prevDateTime);
    }
839634
public function add_month($months)
    {
        $this->time = strtotime("+$months months", $this->time);
        $this->set_timestamp($this->time);
        
        return $this;
    }
1267881
public static function extensionMonth($month) {
        $mes = null;
        switch ($month) {
            case '01':
            case 1:
                $mes = "Janeiro";
                break;
            case '02':
            case 2:
                $mes = "Fevereiro";
                break;
            case '03':
            case 3:
                $mes = "Março";
                break;
            case '04':
            case 4:
                $mes = "Abril";
                break;
            case '05':
            case 5:
                $mes = "Maio";
                break;
            case '06':
            case 6:
                $mes = "Junho";
                break;
            case '07':
            case 7:
                $mes = "Julho";
                break;
            case '08':
            case 8:
                $mes = "Agosto";
                break;
            case '09':
            case 9:
                $mes = "Setembro";
                break;
            case '10':
            case 10:
                $mes = "Outubro";
                break;
            case '11':
            case 11:
                $mes = "Novembro";
                break;
            case '12':
            case 12:
                $mes = "Dezembro";
                break;
        }

        return $mes;
    }
950505
public function modify($modify)
    {
        if (self::$_immutable) {
            self::$_immutable = false;
            $newDate = clone $this;
            $newDate->modify($modify);
            self::$_immutable = true;

            return $newDate;
        } else {
            return parent::modify($modify);
        }
    }
641814
public function addMonthsNoOverflow($value)
    {
        $date = $this->addMonths($value);

        if ($date->getDay() !== $this->getDay()) {
            $date = $date->day(1)->subMonth();
            $date = $date->day($date->getDaysInMonth());
        }

        return $date;
    }