Expiry Plugin works sometimes

I have the expiry plugin set to expiry_date, and send to drafts. I use open office spreadsheet to upload coupons. My problem is this, sometimes the expired coupon is moved to draft, sometimes it is not. Just a note, my spreadsheet is only showing the date, and not the hour, minutes, and seconds. Then the coupon shows an expiration date of 12am, which is what I want. Though the coupons that do not move to draft status show expired on the live coupon. If anyone has some thoughts on this, I would appreciate the help as I want to take my sites live with cp, but can’t until I get this fixed.