Meaning of "Series in Correl() have mismatching frequencies"

As the title says, sometimes when using the correl() function (in my case I am trying to get the correlation between the benchmark and a custom series) I sometimes see this error message - wondering what the meaning of it is?

Not sure if this is in the right forum section to ask this. Thanks in advance!

It is impossible to seek a correlation between values with a frequency of day and values with a frequency of week.

“Custom series” meaning a series you imported?

Perfect alignment of the series is crucial with Correl() or you will get garbage.

We need to do some upgrades to imported series to either auto-detect the frequency or let you tell us the frequency. And fill in any holes. At the moment we simply do not set the frequency of an imported series, so it’s impossible to use them with Correl()

@duckruck/marco In this case, my custom/imported series I created in Excel is comparing between the SP500 and a custom series with daily values.

I am wondering if my imported series has missing values/dates, will that cause the calculation to fail? Are there any other reasons that I could get this error? I’ve just checked my imported series and it is indeed a series with daily values.

EDIT: One more thing to note is that my imported series does not have data for weekends and it MAY exclude holidays (haven’t checked for the latter yet) - Could this be a reason?

Frequency is not inferred from imported series data. There is currently no workaround that will allow you to use data series. Sorry for the inconvenience.