[DateFormat] "YYYY" & "yyyy"

출처 : https://www.youtube.com/watch?v=pgzqVMJUE5Y

Use the correct year format instead 😌

let date = dateOf_01_01_2023()

let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd/MM/YYYY"
dateFormatter.string(from: date)// 01/01/2022

dateFormatter.dateFormat = "dd/MM/yyyy"
dateFormatter.string(from: date)// 01/01/2023