I share your frustration. Its a pet peeve for me as well. I had no idea that the information was actually available in the database..which means implicitly that Adobe could provide it in the history panel.
Adobe actually provides the date time information but only for the following actions: Import, Export, Create Virtual Copy and Snapshot (when you reapply a snapshot)
The problem I find with snapshots is that you have no idea - unless I am missing something - where in the history panel the snapshot was made. So if you have edits after a snapshot or several snapshots its easy to get lost. It seems to me it would be easy to create an entry in the history panel that effectively says ` Created snapshot `time stamp` now' . That would tell you that everthing below is included in the particular snapshot.
There is a (convoluted and not robust) way to include the info about the snapshot in the history. You need to have at least 2 snapshots (the first time you can create 2 snapshots at the same time)
1) Create a snapshot and put a name that identifies it as a baseline (required only the first time)
2) Create a snapshot and save it with the default Date Time
3) Go to the Snapshots panel and apply the "baseline" snapshot
4) Repeat the previous step with the last snapshot
The history will show now both snapshots applied, baseline and the one with the date time