主要思路是使用NSCalendar獲取到當前的月份和日，然后月以100倍之月作為一個數(shù)字計算出來進行對比時間轿曙，獲取到星座匾二，代碼如下哮独，使用Swift 3.0編譯通過

import UIKit
class Constellation: NSObject {
    /**
     通過日期獲取星座
     - parameter date: 日期
     - returns: 星座名稱
     */
    class func calculateWithDate(date: Date) -> String {
        guard let calendar = NSCalendar(identifier: NSCalendar.Identifier.gregorian) else {
            return ""
        }
        let components = calendar.components([.month, .day], from: date)
        let month = components.month!
        let day = components.day!
        
        
        // 月以100倍之月作為一個數(shù)字計算出來
        let mmdd = month * 100 + day;
        var result = ""
        
        if ((mmdd >= 321 && mmdd <= 331) ||
            (mmdd >= 401 && mmdd <= 419)) {
            result = "白羊座"
        } else if ((mmdd >= 420 && mmdd <= 430) ||
            (mmdd >= 501 && mmdd <= 520)) {
            result = "金牛座"
        } else if ((mmdd >= 521 && mmdd <= 531) ||
            (mmdd >= 601 && mmdd <= 621)) {
            result = "雙子座"
        } else if ((mmdd >= 622 && mmdd <= 630) ||
            (mmdd >= 701 && mmdd <= 722)) {
            result = "巨蟹座"
        } else if ((mmdd >= 723 && mmdd <= 731) ||
            (mmdd >= 801 && mmdd <= 822)) {
            result = "獅子座"
        } else if ((mmdd >= 823 && mmdd <= 831) ||
            (mmdd >= 901 && mmdd <= 922)) {
            result = "處女座"
        } else if ((mmdd >= 923 && mmdd <= 930) ||
            (mmdd >= 1001 && mmdd <= 1023)) {
            result = "天秤座"
        } else if ((mmdd >= 1024 && mmdd <= 1031) ||
            (mmdd >= 1101 && mmdd <= 1122)) {
            result = "天蝎座"
        } else if ((mmdd >= 1123 && mmdd <= 1130) ||
            (mmdd >= 1201 && mmdd <= 1221)) {
            result = "射手座"
        } else if ((mmdd >= 1222 && mmdd <= 1231) ||
            (mmdd >= 101 && mmdd <= 119)) {
            result = "摩羯座"
        } else if ((mmdd >= 120 && mmdd <= 131) ||
            (mmdd >= 201 && mmdd <= 218)) {
            result = "水瓶座"
        } else if ((mmdd >= 219 && mmdd <= 229) ||
            (mmdd >= 301 && mmdd <= 320)) {
            //考慮到2月閏年有29天的
            result = "雙魚座"
        }else{
            print(mmdd)
            result = "日期錯誤"
        }
        return result
    }
}

使用方法

let constellation = Constellation.calculateWithDate(date: Date())
print(constellation)