Rated 4 out of 5 stars
Good work was thinking of something like this myself.. it does need configuration option(the options dialog is empty)
Also only part of the extension is working, the browserHistory.addPageWithDetails is not working, only the gBrowser.addTab bit is working with history being cleared and those predefined tabs being added to the tabbar and history.. which is ok for 'Today' but doesn't really make up a timeline of browser history.
Anyway great work hope to see an update soon.
@cleantone "Once I realized that History Rewrite permanently overrides your actual History " well eerh yeah...it uninstalls just fine though, look for firstname.lastname@example.org and delete it if firefox is not removing it.
p.s to the developer maybe you could add a function to fill out a configuration file that takes a snapshot of current history (for user to amend) and keeps the visit dates relative to when alt+y is used.