swift3如何获取明天和昨天的日期(保管特殊情况)新的一个月或新的一年

您应该使用Calendar方法date(byAdding component:)在中午时间进行日历计算.这样做你不必担心这些特殊情况:

Swift 3或更高版本

extension Date {
    static var yesterday: Date { return Date().dayBefore }
    static var tomorrow:  Date { return Date().dayAfter }
    var dayBefore: Date {
        return Calendar.current.date(byAdding: .day, value: -1, to: noon)!
    }
    var dayAfter: Date {
        return Calendar.current.date(byAdding: .day, value: 1, to: noon)!
    }
    var noon: Date {
        return Calendar.current.date(bySettingHour: 12, minute: 0, second: 0, of: self)!
    }
    var month: Int {
        return Calendar.current.component(.month,  from: self)
    }
    var isLastDayOfMonth: Bool {
        return dayAfter.month != month
    }
}

Date.yesterday    // "Oct 28, 2018 at 12:00 PM"
Date()            // "Oct 29, 2018 at 11:01 AM"
Date.tomorrow     // "Oct 30, 2018 at 12:00 PM"

Date.tomorrow.month   // 10
Date().isLastDayOfMonth  // false