Structuring a rolling 12 month comparative analysis

Walt1010 - if you are looking to compare days against the exact point in time 12 months previously you can use DATEADD inside CALCULATE:

CALCULATE( [Measure], DATEADD( 'DateTable'[Date], -1, YEAR ) )

If you'd like to do something similar, but with a range of dates SAMEPERIODLASTYEAR might be more appropriate: https://dax.guide/sameperiodlastyear/ or DATESINPERIOD could help if this is more complex: https://dax.guide/datesinperiod/ 

If you'd like to compare against a rolling average of the last 12 months, you can either use a visual calculation: https://www.youtube.com/watch?v=McRGFB55_kI or a DAX measure: https://www.sqlbi.com/articles/rolling-12-months-average-in-dax/ 

Ultimately which function you use will be determined by the type of comparison you are trying to do. 

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Hi Walt1010 ,

Thank you for reaching out to Microsoft Community.

As per the information provided i understand that you want to compare sickness Leave over the Last 12 Months with the Previous 12 Months .

Make sure you have a Date Table with a continuous date range and a relationship exists between DateTable[Date] and Sickness[Sickness Date].

Sickness Count = COUNTROWS('Sickness')

Sickness Count L12M =

CALCULATE( [Sickness Count], DATESINPERIOD( 'DateTable'[Date], MAX('DateTable'[Date]), -12, MONTH ) )

Sickness Count P12M = CALCULATE( [Sickness Count], DATESINPERIOD( 'DateTable'[Date], EDATE(MAX('DateTable'[Date]), -12), -12, MONTH ) )

If this helped, please mark it as the solution so others can benefit too. And if you found it useful, kudos are always appreciated.

Thanks,
Chaithra E.