Thanks. Now updated that one using the date of the last image. The time was left at 00:00:00 UTC to indicate that any greater precision is unjustified for an observation which took 349 days to complete. (Incidentally, should the time of observation field be pre-filled with that value? It seems to make more sense to me than to have it set to the time of uploading.)
Would you consider running the suggested SQL query to see how many other examples exist? If there are only a (relatively) few perhaps a web page could be created with a list of (username, url) pairs. It would then be up to individuals to update their own observations and would require no further action on you part except, perhaps, re-creating the table every few months.