If you want to find records by pub year it can be tricky since the search is looking at several different MARC tags (008, 260, 264 and 269) so it's possible that the TitleBib has a blank or ?, and that the year is in a different field in the MARC data. Also records can have multiple dates since there's the alt pub date.
The below query only looks at the 269 tag which is where KLAS stores the pub info of the original book that was recorded. The example I used was searching for books published in the 1920s
MARC tag - tag - begins - 269
MARC tag - subfield - begins - c
MARC tag - data - is between - 1920 [and] 1929
