Monitoring with Prometheus 2.0

munin-cgi-graph will graph any time-period you tell it to. Just click on the statically generated graphs to get to it. It'll let you zoom in and out as much as you'd like. The interface is crude, but perfectly workable.

We're not auto-generating the ten-year graphs, but then again, we're also not auto-generating the three-month graphs, or the 'what happened between 18:00 and 18:30 last Tuesday'-graphs either. But the data is there, and the graphs are three mouse-clicks away when needed. As a tool for exploration, for planning and for the occasional reporting it's quite serviceable.

If you do need to auto-generate the graphs for your purposes, then it'd require a bit more work, yes.