Help to calculate values to previous period.

[asuprunova]

Hello, I hope someone will be able to help me with the problem I have. I have a table that specifies student hours by term. For example, I want to know what is the difference in hours between Fall 2020 and Fall 2021. I tried inserting "fake" dates, connected them to the Date dimension table, and implemented the DATEADD function. But it would not give me the result I am looking for. I am suspecting this is because this is not a year-to-year comparison. But I still don't understand why this would not work.  

This is my expression, and I had tables where it work just fine, but not for this one. 

_CH =

VAR _CH =

CALCULATE(CreditHours[_CreditHoursSum], DATEADD(CreditHours[Date],-1,YEAR))

RETURN

_CH

File example here: https://docs.google.com/spreadsheets/d/180vAP4l9JPhAiOrd9LkKLTYmCABcPPY8YKiZtJdEGic/edit?usp=sharing 

I only have fall semester there, but I do have all semesters in the table I need values for. 

[Ashish_Mathur · Accepted solution]

Hi,

You may download my PBI file from here.

Hope this helps.

[asuprunova]

Thank you!

[Ashish_Mathur]

You are welcome.

[NilR]

VAR _CH =

CALCULATE(SUM(CreditHours[_CreditHoursSum]), DATEADD(CreditHours[Date],-1,YEAR))
OR

CALCULATE(SUM(CreditHours[_CreditHoursSum]), PREVIOUSYEAR(CreditHours[Date]))

OR

CALCULATE(SUM(CreditHours[_CreditHoursSum]), SAMEPERIODLASTYEAR(CreditHours[Date]))

[asuprunova]

Yep, I tried what you offered and it does not return results. Also, in my expression the variable_CreditHoursSum was already a summarization, that is why I skipped SUM in my expression.