Results of Period-over-Period Comparison differs with date condition

[jingyu (Jing Yu Lim)]

Hi! I am creating a report that shows a metric value on a monthly basis (i.e Metric Value), along with:

• Value in the previous month (i.e. Metric Value (Prev. 1m))

• % change from the previous month (i.e. Metric Value (% change))

To get only data from the last 5 months (including the current month), the following condition was applied:

The results of the report for the condition above:

However, I noticed that the value of Metric Value (Prev. 1m) for the last entry (i.e. Mar 2023) changes if the condition is changed to last 4 months until today:

The expectation is that Metric Value (Prev. 1m) should be 1,281 for Mar 2023. However, the results show 1,258. Why is this the case? Do I need to ensure that complete months are selected in order for Period-over-Period Comparison to work as per expectation?

[vu.duong]

Hi @jingyu,

Thank you for adding an example, as it made it much easier to investigate the case.

To clarify: By mechanism, Period-over-Period comparison creates the compare period by shifting the original period back/forward, after conditions are applied.
Meaning: if the original range is incomplete, the same goes for the previous range.

So for the 2nd case above (last 4 months until today syntax): Metric Value includes data until Mar 25, making the Metric Value (Prev. 1 month) include data until Feb 25.

To get your expected result, which is complete months: you can use syntaxes like lasts 4 months until next month (like you are already doing), or 4 months ago to this month end, etc. assuming you don’t have past data mixed with future data in your dataset.

Hope it’s helpful!