Cipher

OK , I know it is about the beep function, and I need to convert the numbers to a media or something, but what sofrware do I need ?

I am totally lost here....
dd/{mm}/1949 1st
dd/{mm}/1984 2nd
dd/{mm}/1946 2nd
dd/{mm}/1955 1st
dd/{mm}/1937 1st
dd/{mm}/1981 3rd
I know I need to [spoiler], but what is the key word here? I tried friday, black friday, but they all seem not right....