can you edit an excel calender online

ok i want to put a calender on my web site made with excel
where if free is green background behind each date and if not red background
ok i can work out how to do that part in design but once its on the web page can i let any one change the color background from green to red etc without it being downloaded changed and uploaded again
i have looked at various free calenders online but not simple enough
ok hope i ant broke any rules this time as i am only asking a question if it can be done
cheers
Doug
ok have made the calader as shown i saved as web page what next to make editable