# Function diffPastMonth
diffPastMonth(
measure,name?):CalculatedMeasure
Creates a calculated measure that calculates the difference between this month's data and the data from the previous month for the given measure.
The date dimension will be dynamically taken from the query that uses the returned measure.
# Parameters
| Parameter | Type | Description |
|---|---|---|
measure | Measure | Measure to apply difference to |
name? | string | Name for the new measure |
# Returns
A calculated measure instance
# Example
Calculate the difference between this month's total cost and the previous month's total cost from the Sample Ecommerce data model.
measureFactory.diffPastMonth(measureFactory.sum(DM.Commerce.Cost))