Gets the total number of months _in this period.
!(p)
This returns the total number of months _in the period by multiplying the
number of years by 12 and adding the number of months.
!(p)
This instance is immutable and unaffected by this method call.
@return the total number of months _in the period, may be negative
Gets the total number of months _in this period. !(p) This returns the total number of months _in the period by multiplying the number of years by 12 and adding the number of months. !(p) This instance is immutable and unaffected by this method call.
@return the total number of months _in the period, may be negative