This might take a bit so I apologize for that. Im writing a story that takes place in a separate universe with a different species. In this universe 48 hours is 1 day, and 20 years(for us) is 1 year(for them). In my notes i have writen "80h years - 1h lifetime = 75D years(1500h years) - 1D lifetime" H being us, D being them. My question is because the day system is different is the 1500 part correct? It confused me to think about so I would appreciate help.