Keep track of how much time you spend on the web, and where you spend it. Ticker widget shows (1) time spent at the current site and (2) total time spent on the web today. Summary page sums up data for the past 70 days, 10 weeks, and 6 months.
By default Firefox provide five options to delete browsing history, which includes Last hour, last two hours, last four hours, last day and everything. This add-on deletes the history at Minute, Hour, Days and Week level.