Make a program in PHP that will print out only on Mondays of every week and month a message

I want to make a program in PHP that will print out only on Mondays a message like "today is cinema day", but if it's not Monday and e.g. is Friday the program, must print "Cinema day is in 2 days". Is there any function for this or i must make on my own. My research so far hasn't results.

Thanks in advance!