The function MONTH converts a date or time period to a month in number format.
This function is useful if you want to easily compare months to see if they're the same.
Syntax
MONTH(Value to convert, [Time period method])
Arguments
| Argument | Data type | Description |
| Value to convert | Date, time period | The date or time period to convert to a month, as a number. |
| Time period method (optional) | Keyword | Determines whether to extract the month from the start, middle, or end of a time period. |
The keywords for the time period method argument are:
- START, the default method, returns the month for the first date in the time period
- MID, which returns the month for the date in the middle of the time period
- END, which returns the month for the last date in the time period
The MONTH function returns a number.
Excel equivalent
Examples
Convert a Date to a Number data type
In this example, the line item Date is in Date format. The line item Number returns the Number format of the month using the formula MONTH(Date).
| Jan 25 | Feb 25 | Mar 25 | Apr 25 | May 25 | |
| Date | 01/01/2025 | 02/02/2025 | 03/03/2025 | 04/04/2025 | 05/05/2025 |
NumberMONTH(Date) | 1 | 2 | 3 | 4 | 5 |
Convert a Time-formatted list item to a Number data type
In this example, the target module is dimensioned by a list with a property called Months. This is the List as viewed in Grid View.
| Parent | Code | Months | |
| 1 | Dec 21 | ||
| 2 | Jan 21 | ||
| 3 | Sep 22 | ||
| 4 | Jul 24 | ||
| 5 | Dec 23 |
The line item Input is in Time Period format in Month, and it has the formula List.Months to return the Months list items from the list. The line item Number returns the Number format of the month using the formula MONTH(Input).
| 1 | 2 | 3 | 4 | 5 | |
InputList.Months | Dec 25 | Jan 21 | Sep 22 | Jul 24 | Dec 23 |
NumberMONTH(Input) | 12 | 1 | 9 | 7 | 12 |
The example below shows MONTH(Value to convert). The values to convert are taken from the Product date and Month period line items. They're date and time period formatted, respectively. The MONTH function returns the same result.
| Key dates | Expiry dates | |
| Product released | 16/02/2016 | 23/08/2017 |
| Month period | Feb 16 | Aug 17 |
Product month
| 2 | 8 |
Month number
| 2 | 8 |
The next example shows MONTH(TIME. 'Period'). An explicit time reference is used instead of a line item.
| Key dates | |
Year Number
| 4 |
The final example shows the effect of the Time period method argument. An explicit time reference is used with a keyword to determine which date in a time period to extract the month from.
| Product: Plums | |
| Start of fiscal year | Jan FY2019 |
Month Start
| 1 |
Month Mid
| 2 |
Month End
| 3 |
