1. Heyday is a band from Belfast, Northern Ireland, with five members:
Paul Walker JR,Dex McDonnell, Barry Costello, Seamus Nolan and Niall Connolly
They write rock/indie songs. 2. Heyday was a hard rock band from USA, they released one album in 1994. 3. Heyday was also a rock band from Germany , they released one album "Wide awake" in 2002 and two singles "Could Be Day, Could Be Night" and "Summer". They were successful with "Could Be Day, Could Be Night" and played on many radio stations but broke up in 2005.