Hey @TristanEarl 

Alerts can be set only on a daily or hourly interval chart.
From the current default options, it looks like only previous day’s value and the previous week’s value is available for comparison. I can see some value in how it might help to compare it to a higher custom time interval for alerting. Here’s the idea section where in you can submit this as a potential feature idea.

You can try using the Compare to past feature on the event seg chart to go beyond a custom date range, but not aware of any direct workaround to combine this with the alerts capability.
 

Hope this helps.

Thank you @Saish Redkar.  In lieu of that feature, is there a way to write a formula that computes the ratio between data points and their 3-month-ago values?  I’m thinking I can trigger an alert if that ratio gets too big.  Something like :

PROPAVG(A)/PROPAVG(A, -90)

Is this in any way possible?

Update:  I’m trying the Compare to past feature you mentioned and seeing if I can get alerts to fire when the ratio falls below a certain threshold.

I don’t think PROPAVG formula can take in the days parameter.
You can play around the ROLLWIN formula If the use case fits.

Maybe something like this - ROLLWIN(PROPAVG, A, 90)

Looks like the Compare to past feature gives us what we need.  With that we can compute the differences between 3-month timespans and set up an alert if that difference reaches a certain threshold.