是 swift 中另一个日期的同一周、月、年的日期

您可以使用日历方法isDate(equalTo:granularity:)进行如下判断:

Xcode 11 • Swift 5.1

extension Date {

    func isEqual(to date: Date, toGranularity component: Calendar.Component, in calendar: Calendar = .current) -> Bool {
        calendar.isDate(self, equalTo: date, toGranularity: component)
    }

    func isInSameYear(as date: Date) -> Bool { isEqual(to: date, toGranularity: .year) }
    func isInSameMonth(as date: Date) -> Bool { isEqual(to: date, toGranularity: .month) }
    func isInSameWeek(as date: Date) -> Bool { isEqual(to: date, toGranularity: .weekOfYear) }

    func isInSameDay(as date: Date) -> Bool { Calendar.current.isDate(self, inSameDayAs: date) }

    var isInThisYear:  Bool { isInSameYear(as: Date()) }
    var isInThisMonth: Bool { isInSameMonth(as: Date()) }
    var isInThisWeek:  Bool { isInSameWeek(as: Date()) }

    var isInYesterday: Bool { Calendar.current.isDateInYesterday(self) }
    var isInToday:     Bool { Calendar.current.isDateInToday(self) }
    var isInTomorrow:  Bool { Calendar.current.isDateInTomorrow(self) }

    var isInTheFuture: Bool { self > Date() }
    var isInThePast:   Bool { self < Date() }
}