I was looking for something similare and found this one - Desktop
Calendar -
http://www.glenn.delahoy.com/software/index.shtml
Description from the site:
"A small calendar and event reminder that unobtrusively sits on your
desktop and is ready to use any time. No taskbar button, no system tray
icon, the calendar is transparent so it's not an eyesore and consumes
very little memory (less than 600KB idle). Enter as many daily or
regular events as you like. Float your mouse over a day to see all
events for the day. Shows a short list of upcoming events below the
calendar. Fonts, colours and tooltips are customisable so it blends in
with your desktop colour and font schemes. Events may be colour coded
for quick identification. First day of the week is customisable. Scales
as small or as big you want. Please note: this application will only
work on Windows 2K/XP."