원하는 날짜 만들기 → DateComponents 이용 (옵셔널)

let dateComponents = DateComponents(year: 2000, month: 7, day: 12, hour: 4)
let customDate = Calendar.current.date(from: dateComponents)

print(dateFormatter.string(from: customDate)

날짜 더하기

let curDate = Date()
let addDate = Calendar.current.date(byAdding: .day, value: 1, to: curDate)
let addHour = Calendar.current.date(byAdding: .hour, value: 1, to: curDate)

print(curDate) //2022-08-10 11:01:07 +0000
print(addDate) //Optional(2022-08-11 11:01:07 +0000)
print(addHour!) //2022-08-10 12:01:07 +0000