I recently made a change to a WordPress site I maintain, and I expect this change to dramatically improve page load time. So far, it seems to be working.
However, in the coming weeks and months I would like to be able to look back in Google Analytics and see an indication of the exact date I made the change, so that I'll be able to see that, if my page load times improved, whether that improvement correlated with the change I made. See this screen shot for an idea of what I'm talking about:
I could just write down the date that I made the change somewhere, but it'll be easier to keep track of and not lose if it could somehow be stored right in GA itself. Also, there are likely other performance improvements coming up, and I'd like to do the same for them, so it's not just a one-off problem.
Does anyone know of a way to do this in Google Analytics?