Zooropa is my favorite U2 album along Boy, TUF and The Passengers' album, so Dirty Day has a special place in my heart.
The bass line is amazing and I like how low key the song sounds until it has those bursts of excitement. Of course, I love how it sounds just like midnight. It is a cool song. However, it is not in my top tier tracks of Zooropa.
Lyrically, I think it is a little overrated. Maybe I don't get it, but for me it is just a bunch of random punchlines that sounds cool individually, but that don't go anywhere together.