.... though I'm reasonably sure I'm not, so...
Here's what I have after a little playing around...
Today
[=isequal(formatdate([Date Imported,0],dd//MM//yyyy),formatdate(now(),dd//MM//yyyy),8)]=1
Yesterday
[=isequal(formatdate([Date Imported,0],dd//MM//yyyy),formatdate(math(now()-1),dd//MM//yyyy),8)]=1
This Week
[=isequal(if(isequal(formatdate([Date Imported,0],%W),00),formatdate(math([Date Imported,0]-formatdate([Date Imported,0],dd)),yyyy%W),formatdate([Date Imported,0],yyyy%W)),if(isequal(formatdate(now(),%W),00),formatdate(math(now()-formatdate(now(),dd)),yyyy%W),formatdate(now(),yyyy%W)))]=1
Last Week
[=isequal(if(isequal(formatdate([date imported,0],%W),00),formatdate(math([date imported,0]-formatdate([date imported,0],dd)),yyyy%W),formatdate([date imported,0],yyyy%W)),ifelse(isequal(formatdate(now(),%W),00),math(formatdate(math(now()-formatdate(now(),dd)),yyyy%W)-1),isequal(math(formatdate(now(),%W)-1),0),formatdate(math(now()-formatdate(now(),dd)),yyyy%W),1,math(formatdate(now(),yyyy%W)-1)))]=1
This Month
[=isequal(formatdate([Date Imported,0],MM//yyyy),formatdate(now(),MM//yyyy),8)]=1
Last Month
[=isequal(formatdate([Date Imported,0],MM//yyyy),if(isequal(formatdate(now(),MM),01),12,padnumber(math(formatdate(now(),MM)-1),2))//if(isequal(formatdate(now(),MM),01),math(formatdate(now(),yyyy)-1),formatdate(now(),yyyy)),8)]=1
This Year
[=isequal(formatdate([Date Imported,0],yyyy),formatdate(now(),yyyy),8)]=1
Last Year
[=isequal(formatdate([Date Imported,0],yyyy),math(formatdate(now(),yyyy)-1),8)]=1
It dawned on me that we can completely side-step the whole locale issue by formatting the library field too, so these should all work 'as-is', regardless of where you are.
I think there may be an issue with week numbers. I'm waiting for some feedback on this elsewhere, but for now, where week 52 or 53 spans into the new year, the new year part of the week is given week number zero. I've skirted around this for the moment by forcing "Last Week" to use week 52 if it is zero or one. This does mean that a few "Week 53's" might get lost in the listings, I'll update if I hear back on this issue. Like wise, for "This Week", it will match on week zero, missing the beginning of the week that was actually in last year.
These are for the OCD MC users amongst us. By default, the quick and easy way to do these is not as precise. 'The last week' is actually the last seven days, 'today' is actually the past 24 hours, and so on, these however, do what they say on the tin, with the small exception outlined in the "Week" searches above.
You can edit them to work with other date fields. These all use [Date Imported,0]. Switch those to [Last Played,0] to get a neat play stats view, for example.
Enjoy, give them a bash, let me know if any mistakes slipped through, or if you know of a more streamlined way to reach these target lists, please share.
-marko