Something I noticed on the date Rosenstein signed the FISA application.

Looking just below the redacted part of the date, it matches the bottom of the '1' in 17. It isn't the slash because the slash also drops down below the redaction.

So, looking at the space between slashes separating the 6 and the 17 Tells me there is another number in there. Since there isn't a 'tail' below the left side of the redaction tells me it isn't '11' and June has only 30 days so it isn't '31'

That leaves either '01' or '21'. Most people skip the 0 when writing the 1st and folks that do include it also include it on the month.

So, my guess would be the date Rosenstein signed the application is 6/21/17