Olio, you may well have it. 18 Feb is likely the correct day. I had posted 17 Feb as this is what I read according to people "who work for the company", (like that means they know a whole lot about their company right?).
In any event, HWP's formula is apparently to report 12 working days after the close of the quarter. Normally, that makes 17 Feb correct...except for a slight oversight: 16 Feb is Presidents' Day. Isn't THAT special?! The HWPers may be working that day, but not we traders. The 18th it is.
(I still wouldn't consider buying until after the announcement: I'd rather give up the inital pop, were there to be one, and get on the longer running train, than deal with a gap down on 19 F