"Then and now"
Translation:Damals und heute
I believe jetzt is a better translation for "now". Nun is more of an interjection like "Now, what's this?" almost like the interjection "well", but with vague implications of currentness.
As for the sentence above, "Damals und heute" seems like it can be loosely translated to "then and now", you might also say more literally "those days and these days".