Same Period Last Year

[koorosh]

Hi, Why sameperiodlastyear did not result in one year back from the date column selected?

[VilmarSch]

Apparently it's normal:

The SAMEPERIODLASTYEAR is equivalent to DATEADD(dates, -1, year).
Its biggest year in the date table is 2019, so SAMEPERIODLASTYEAR will show the previous year, i.e. 2018.
Its smallest year in the date table is 2014, so SAMEPERIODLASTYEAR will not show the previous year, i.e. 2013.

[koorosh]

Why it is normal that does not show 2013? If you use DATEADD(dates, 1, year), and the biggest one is 2016 (attached file) the result shows 2017.

[Ahmedx]

SELECTCOLUMNS('Table',"Date",SAMEPERIODLASTYEAR('Table'[Date]))
will give empty at the beginning , go down and you see dates

[koorosh]

Thanks. Why there are no empty rows or 2013 rows in the sameperiodlastyear table?
And why there is no 2013 rows in selectcolumn table and it shows empty rows ? 

[Ahmedx]

it works, it moves the date back one year.
you will lose the last year, and you will not see the first year, since it is not in the table.
if your date is early 2014 and late 2023
you will see only 2014 and 2022, and do not see 2013 because it is not in the table

[koorosh]

Do you mean 2013 will not be in the output? why?

[Ahmedx]

you need other features

[koorosh]

Thanks.But my question is , in the defination of this function was written "Returns a table that contains a column of dates shifted one year back in time from the dates in the specified dates column, in the current context."
Why I can not get this result?