It's a filter, yes, but a filter based on picking different cutoff points in an ordered column: 7 days, 30 days, 90 days, etc. I often find myself using these things as a roundabout way to sort a column, where first I get the last 7 days, then the last 30 and skip the ones I'd already seen, etc. Though it really depends on the app whether users would do that. I recall doing that most recently on an apartment-search site that offered that kind of filter but no sorting: I wanted to see the most recent listings, so first I saw the most recent listings, then loosened the filter to the next-most-recent category, etc. Would've just preferred a Craigslist style sort so I could continue scrolling down instead of doing the filter-loosening thing.