Hi Sara. You can filter on Tasks where the Planned Completion Date is less than the Projected Completion Date (in other words, "it's starting to slip") in a filter using a special keyword called FIELD like this:
plannedCompletionDate= FIELD: projectedCompletionDate plannedCompletionDate_Mod=lt
My initial idea was that when you set a planned completion date (or drive it via a planned start date and a duration), that the projected end date would be equal. Over time, as a project tends to hit delays and the projected completion dates "stretch" you could use the filter above to detect those tasks that have slipped and were edited within the last 24 hours.
Given your latest post, though, I now see that you're trying to find where the Planned Completion Date has changed; similar, but different. If the "normal behavior" results in the Projected Completion Date being equal to the Planned Completion Date (when the latter is changed), perhaps you could use:
planned CompletionDate= FIELD : projectedCompletionDate plannedCompletionDate_Mod= eq
and (optionally) add the "within the past 24 hours" to the filter as well, but it seems a bit loose to me; and where reports are unreliable, people will not rely on them (hence the name, I guess).
Instead, I'd suggest you consider a Baseline Task Report, which would allow you to compare What Was the Planned Completion Date (in the Baseline Task) against What Is the Planned Completion Date (in the always-current Task).
You can create the baselines manually to test out the theory, and if you love it, automate the creation of Baselines (e.g. "take a Baseline any time the Planned Completion Date changes"...assuming we could noodle a filter out that would detect that), using our schedulable Create Baseline AtApp.
Regards,
Doug
