Time sensitive links with pictures

I'm trying to have a picture that is a link to another site that the link changes based on the time of day.

I have a restaurant website and we have different delivery services based on the time of the day (not worth getting into for now), but in order to avoid going into the back end and changing the link on the picture every day in the morning and then again at 5pm, I'd like some sort of auto work around that changes the link automatically.

I want the picture and the link to be the same throughout the day, just the link change to the designated delivery service based on the time of day. For instance: From 10:30am until 5pm, I want the delivery button to go to our foodler.com page and then from 5pm until 10am I want it to go to our menufy.com page.

The website is basic html and css. Any suggestions?

Currently it looks like this:

a href="http://ift.tt/1AOZrON" target="_new"> img src="/images/orderdelivery.png" alt="Order UMelt Delivery!" style="width:150px;height:40px;border:0" onmouseover="this.src='/images/orderdeliverymouse.png'" onmouseout="this.src='/images/orderdelivery.png'" />

Listen I'm pretty new to website coding and I was given a really nice page that I pretty much mickey mouse together with changes now so I apologize if these seems like a simple task.

Thanks, Jonathan