element change depending on event on google calendar

So I can see that wordpress has a pretty much ready-made plugin for this http://ift.tt/1oOpMT9 but I'm working with a non-wordpress site and then I know making wordpress plugins work on non-wordpress sites are usually more work than they're worth. There are also ways to use javascript to do hard-code what I'm trying to do. Furthermore, I've tried playing with Google Calendar API to do this, but nothing's really working.

Is there a way to set up an image to display that is pulling from a Google calendar? Specifically I have an image that says "Opened" for when the client's store is opened, but because the hours vary so often and the client is not good with computers they want to just make a daily event on their Google calendar called "opened" and have their website display the "opened" picture for as long as the calendar event is going on. So if the store opened at 9 am tomorrow, tomorrow at 9 am the "opened" button would appear, and then disappear when the event ends at 10pm.