DiffInMonths calculation is invalid

[wesuccess666]

Hello,

I encountered an issue with the following code:
DiffInMonths is invalid, It's not every month is 30 days

// DiffInMonths gets the difference in months.
// 相差多少月
func (c Carbon) DiffInMonths(carbon ...Carbon) int64 {
	start, end := c, c.Now()
	if len(carbon) > 0 {
		end = carbon[len(carbon)-1]
	}
	return int64(math.Floor(float64((end.Timestamp() - start.Timestamp()) / (30 * 24 * 3600))))
}

In version 1.6.9, DiffInMonths is right

func (c Carbon) DiffInMonths(carbon ...Carbon) int64 {
	end := c.Now()
	if len(carbon) > 0 {
		end = carbon[len(carbon)-1]
	}
	startYear, startMonth, startDay := c.Date()
	endYear, endMonth, endDay := end.Date()

	diffYear, diffMonth, diffDay := endYear-startYear, endMonth-startMonth, endDay-startDay
	if diffDay < 0 {
		diffMonth = diffMonth - 1
	}
	if diffYear == 0 && diffMonth == 0 {
		return int64(0)
	}
	if diffYear == 0 && diffMonth != 0 && diffDay != 0 {
		if int(end.DiffAbsInHours(c)) < c.DaysInMonth()*HoursPerDay {
			return int64(0)
		}
		return int64(diffMonth)
	}
	return int64(diffYear*MonthsPerYear + diffMonth)
}

Thanks!

[gouguoyin]

The next version will fix

[gouguoyin]

Fixed in version 2.2.4