How To Use System Variable ‘FirstMonthOfYear‘ In Qlik Sense

The system variable ‘FirstMonthOfYear ‘ defines which month to use as first month of the year, which can be used to define financial (fiscal) years that use a monthly offset.

Even by modifying the ‘FirstMonthOfYear ‘ value in default script, the value will not be used in function YearStart(date[, period_no[, first_month_of_year]])
For example starting July 1. Set FirstMonthOfYear=7 in script, 
yearstart ('19/07/2017') will return ‘01/01/2017’
 
The expected result would be ‘01/07/2017’

Environment:
Qlik Sense Nov 2018
Qlik Sense Feb 2019

The variable ‘FirstMonthOfYear‘ is currently unused but reserved for future use as mentioned in Qlik Help Number Interpretation variables (Feb 2019).

The variable FirstMonthOfYear can be a useful environment variable and it can be passed in to any function which has an argument related to the first month of the year. 

For example, with FirstMonthOfYear=7:

yearstart ('19/10/2001', 0, $(FirstMonthOfYear)) would return the 1st of July, 2001


For more information about year start please review the product documentation for the Year Start function (Feb 2019).