Sorting Issue with Numeric Dates

I have created a numeric date field and am using it for most of my collections now. However, when I sort by it within the collection, I keep getting these odd little glitches where things are correct by month and the months are in order, but the days are not. I cannot figure out the logic of the results at all. I tried redoing the index, since that is all that I could think of, but nothing has changed.
Is there a way to fix this universally? I have already loaded several thousand records this way.

Could you clarify a few things for me:

It looks like you created a new element (Numeric), and are displaying that as the date, yes?

Are you entering the data as something numeric, but then filtering it for the more readable display?
That is, looks like 1917-04-05 in the data entered turns into “1917 April 5” in the display. If that’s close, what is the format that the data is entered in?

I’m not 100% sure that there are no glitches in the months, too. On page 10 of the search you linked to, I noticed an Item that has no month or day information among other mixed up dates.

I left the date field as it is for the display and added another field under the type metadata that is hidden from users. So, the numeric date for the 1917 item that you mention on page 10 with only a year is 19179999.
Other numeric dates in that field are formatted as just a number. So, 19170523 for May 23, 1917, which archivists refer to as 1917 May 23, and so. That should come before 19170601 in the sort that is based on the numeric date field, but it doesn’t always for some reason.

It looks like the problem might be in the search links generated. Numeric probably wouldn’t be among the Dublin Core metadata, but rather under Item Type Metadata. Thus, the link you are constructing using Dublin Core will get confused.

If a link like

swapping out Dublin+Core for Item+Type+Metadata gives the expected results, it seems like just a matter of making sure that those links use that change in how you construct them.