I notice that a lot of time I search for <searchterm> from the last week because “since yesterday” only goes back to the previous midnight, which in the hours between midnight and bedtime is entirely inadequate.
Assuming that the search engine is less hampered by requests for all the <searchterm> since fairly recently than by the same searchterm request since farther back (it certainly takes longer to search farther back) – I’d use “In the last 48 hours” in lieu of “last week” for 99% of the searches where I currently use “last week”.
If this is a area that you can readily change with non-hacking preferences (like y’all did when you disincluded “Search All Open Forums” a couple years back), my suggestion is that you consider adding this option, as I doubt that I’m the only one who is quite often interested in the ~48hour timeframe when I search.