public function subSeconds(int $secs = 1): Jalalian
    {
        return static::fromCarbon($this->toCarbon()->subSeconds($secs));
    }

    public function equalsTo(Jalalian $other): bool
    {
        return $this->equalsToCarbon($other->toCarbon());
    }

    public function equalsToCarbon(Carbon $carbon): bool
    {
        return $this->toCarbon()->equalTo($carbon);
    }

    public function greaterThan(Jalalian $other): bool
    {
        return $this->greaterThanCarbon($other->toCarbon());
    }

    public function greaterThanCarbon(Carbon $carbon): bool
    {
        return $this->toCarbon()->greaterThan($carbon);
    }

    public function lessThan(Jalalian $other): bool
    {
        return $this->lessThanCarbon($other->toCarbon());
    }

    public function lessThanCarbon(Carbon $carbon): bool
    {
        return $this->toCarbon()->lessThan($carbon);
    }

    public function greaterThanOrEqualsTo(Jalalian $other): bool
    {
        return $this->greaterThanOrEqualsToCarbon($other->toCarbon());
    }

    public function greaterThanOrEqualsToCarbon(Carbon $carbon): bool
    {
        return $this->toCarbon()->greaterThanOrEqualTo($carbon);
    }

    public function lessThanOrEqualsTo(Jalalian $other): bool
    {
        return $this->lessThanOrEqualsToCarbon($other->toCarbon());
    }

    public function lessThanOrEqualsToCarbon(Carbon $carbon): bool
    {
        return $this->toCarbon()->lessThanOrEqualTo($carbon);
    }

    public function isStartOfWeek(): bool
    {
        return $this->isSaturday();
    }

    public function isSaturday(): bool
    {
        return $this->isDayOfWeek(Carbon::SATURDAY);
    }

    public function isDayOfWeek(int $day): bool
    {
        Assertion::between($day, 0, 6);
        return $this->toCarbon()->isDayOfWeek($day);
    }

    public function isEndOfWeek(): bool
    {
        return $this->isFriday();
    }

    public function isFriday(): bool
    {
        return $this->isDayOfWeek(Carbon::FRIDAY);
    }

    public function isToday(): bool
    {
        return $this->toCarbon()->isToday();
    }

    public function isTomorrow(): bool
    {
        return $this->toCarbon()->isTomorrow();
    }

    public function isYesterday(): bool
    {
        return $this->toCarbon()->isYesterday();
    }

    public function isFuture(): bool
    {
        return $this->toCarbon()->isFuture();
    }

    public function isPast(): bool
    {
        return $this->toCarbon()->isPast();
    }

    public function toArray(): array
    {
        return [
            'year' => $this->year,
            'month' => $this->month,
            'day' => $this->day,
            'dayOfWeek' => $this->getDayOfWeek(),
            'dayOfYear' => $this->getDayOfYear(),
            'hour' => $this->hour,
            'minute' => $this->minute,
            'second' => $this->second,
            'micro' => $this->toCarbon()->micro,
            'timestamp' => $this->toCarbon()->timestamp,
            'formatted' => $this->toString(),
            'timezone' => $this->timezone,
        ];
    }

    public function getDayOfWeek(): int
    {
        if ($this->isSaturday()) {
            return 0;
        }

        if ($this->isSunday()) {
            return 1;
        }

        if ($this->isMonday()) {
            return 2;
        }

        if ($this->isTuesday()) {
            return 3;
        }

        if ($this->isWednesday()) {
            return 4;
        }

        if ($this->isThursday()) {
            return 5;
        }

        return 6;
    }

    public function isSunday(): bool
    {
        return $this->isDayOfWeek(Carbon::SUNDAY);
    }

    public function isMonday(): bool
    {
        return $this->isDayOfWeek(Carbon::MONDAY);
    }

    public function isTuesday(): bool
    {
        return $this->isDayOfWeek(Carbon::TUESDAY);
    }

    public function isWednesday(): bool
    {
        return $this->isDayOfWeek(Carbon::WEDNESDAY);
    }

    public function isThursday(): bool
    {
        return $this->isDayOfWeek(Carbon::THURSDAY);
    }

    public function getDayOfYear(): int
    {
        $dayOfYear = 0;
        for ($m = 1; $m < $this->getMonth(); $m++) {
            if ($m <= 6) {
                $dayOfYear += 31;
                continue;
            }

            if ($m < 12) {
                $dayOfYear += 30;
                continue;
            }
        }

        return $dayOfYear + $this->getDay();
    }

    public function toString(): string
    {
        return $this->format('Y-m-d H:i:s');
    }

    public function format(string $format): string
    {
        return CalendarUtils::strftime($format, $this->toCarbon());
    }

    public function __toString(): string
    {
        return $this->toString();
    }

    public function ago(): string
    {
        $now = time();
        $time = $this->getTimestamp();

        // catch error
        if (!$time) {
            return false;
        }

        // build period and length arrays
        $periods = ['ثانیه', 'دقیقه', 'ساعت', 'روز', 'هفته', 'ماه', 'سال', 'قرن'];
        $lengths = [60, 60, 24, 7, 4.35, 12, 10];

        // get difference
        $difference = $now - $time;

        // set descriptor
        if ($difference < 0) {
            $difference = abs($difference); // absolute value
            $negative = true;
        }

        // do math
        for ($j = 0; $difference >= $lengths[$j] and $j < count($lengths) - 1; $j++) {
            $difference /= $lengths[$j];
        }

        // round difference
        $difference = intval(round($difference));

        // return
        return number_format($difference) . ' ' . $periods[$j] . ' ' . (isset($negative) ? '' : 'پیش');
    }

    public function getTimestamp(): int
    {
        return $this->toCarbon()->getTimestamp();
    }

    public function getNextWeek(): Jalalian
    {
        return $this->addDays(7);
    }

    public function addDays(int $days = 1): Jalalian
    {
        return static::fromCarbon($this->toCarbon()->addDays($days));
    }

    public function getNextMonth(): Jalalian
    {
        return $this->addMonths(1);
    }
}