Appointments+ fails to exclude selected date

Appointments+, which works perfectly for me most of the time is NOT excluding a date I added (January 22, 2016) when our office will be closed. See http://www.ucsf-ahp.org/hiv/hcat/make-your-appointment/?app_service_id=1

I'm using the most current version of the plugin and other dates that are "unavailable" per the Exclusions setting.

Can't figure out what's wrong. Please advise. Screenshots available if you want.

Many thanks in advance!
Lisa