This question is for PHP coding and not using MySQL.

I am trying to figure out the code to make:

if monday then
code

else
code

I would really like to get this based on SERVER time. Ideally I would like a section of code to execute if the day is Monday, and the server time is 4-7pm.

The reason for this is to have a 'live chat' image to appear, that gives a link to a chat room, but I only want it to appear on Mondays from 4-7.

Can someone help me with this?

TIA!