Hi @lorimer,
we summarized a few use cases (including quill, HW) here.
Each neuron has a new field voting_power_refreshed_timestamp_seconds that should give you this information.
IIUC your known neuron (with name Lorimer) has the ID 16459595263909468577. You can then call the NNS governance’s endpoint list_neurons to list this neuron - for example on the dashboard using length 1 and entering the ID as the ID you want to be listed.
This will return the neuron info, incluing the line
voting_power_refreshed_timestamp_seconds = opt (1_739_350_820 : nat64); - which you can then convert to the date/time when your neuron was last refreshed using a converter (like this).
Someone could of course build a frontend to show this with less manual. Maybe this is actually something that would be useful to display for known neurons on pages where they are listed…