The person who posted the Spencer account found a couple of WEB references.
http://bbs.cresnet.org/library/bstudy/bs/bibl22.txt
This has the Spencer account as well as some followup from the
Minneapolis Star. That quotes Hill as saying:
. Since this event came to my attention about two years ago, I have
misplaced the source information. I can only say that had I not
considered the source to be completely reliable, I would not have used
it in the first place. I am interested in facts, not fiction.
http://tommy.jsc.nasa.gov/~woodfill/SPACEED/SEHHTML/still.html
This one uses the 'missing day' as a springboard for an educational
exercise, with study questions (how could it happen? would the sun
standing still be the only noticible effect? etc).