Implement MONTH function

[stanim]

Description

Returns the month of a date represented by a serial number. The month is given as an integer, ranging from 1 (January) to 12 (December).
https://support.microsoft.com/en-us/office/month-function-579a2881-199b-48b2-ab90-ddba0eba86e8

Syntax

MONTH(serial_number)

The MONTH function syntax has the following arguments:

• Serial_number Required. The date of the month you are trying to find. Dates should be entered by using the DATE function, or as results of other formulas or functions. For example, use DATE(2008,5,23) for the 23rd day of May, 2008. Problems can occur if dates are entered as text.