Monthly SEO reports are built for a cadence the index does not keep. You close the month, screenshot the chart, and assign the movement to whatever shipped in those thirty days. Three months later the same pages finally move, and a different team takes credit.
We keep seeing the same pattern: a content rewrite in April, a template change in May, a crawl-budget tweak in June, and a traffic step-change in August. The August report names August. The work that mattered is already out of the slide.
If your reporting window is shorter than the index, you will keep writing fiction.
What to do instead
Keep the change on the calendar until it is old. Annotate the week you shipped and the week Googlebot actually fetched it. Then look at clicks and sessions in the weeks after that — not the week of the pull request.
The 90-day lag is not an excuse to wait forever. It is a reason to stop closing the book every thirty days and calling it science.