如何获得星期一&x27；s当前周的swift日期

我想知道本周星期一的日期。在我的表视图中，这被视为一周的第一天。 我还需要得到本周的星期日。在我的表视图中，这被视为一周的最后一天

当前尝试：

let date = NSDate()
let calendar = NSCalendar.currentCalendar()
calendar.firstWeekday = 1
//attempt to changefirstday

let dateFormatter = NSDateFormatter()
let theDateFormat = NSDateFormatterStyle.ShortStyle
let theTimeFormat = NSDateFormatterStyle.ShortStyle
dateFormatter.dateStyle = theDateFormat
dateFormatter.timeStyle = theTimeFormat

let currentDateComponents = calendar.components([.YearForWeekOfYear, .WeekOfYear ], fromDate: date)
let startOfWeek = calendar.dateFromComponents(currentDateComponents)
print("startOfWeek is \(startOfWeek)")
let stringDate = dateFormatter.stringFromDate(startOfWeek!)
print("string date is \(stringDate)") //This is returning Sunday's date

尝试使用：

calendar.firstWeekday = 2

编辑

更具体地说：

NSCalendar.currentCalendar（）

返回用户日历。根据文件：

返回的日历由当前用户所选系统区域设置的设置与用户在系统首选项中指定的任何自定义设置叠加而成

如果您希望始终将星期一作为第一天，我认为您应该使用：

let calendar = NSCalendar(calendarIdentifier: NSCalendarIdentifierGregorian)!
calendar!.firstWeekday = 2

---

我编写了日期扩展来获取某些工作日的日期，下面是使用Swift 5的简单性

Date.today()                                  // Oct 15, 2019 at 9:21 AM
Date.today().next(.monday)                    // Oct 21, 2019 at 9:21 AM
Date.today().next(.sunday)                    //  Oct 20, 2019 at 9:21 AM


Date.today().previous(.sunday)                // Oct 13, 2019 at 9:21 AM
Date.today().previous(.monday)                // Oct 14, 2019 at 9:21 AM

Date.today().previous(.thursday)              // Oct 10, 2019 at 9:21 AM
Date.today().next(.thursday)                  // Oct 17, 2019 at 9:21 AM
Date.today().previous(.thursday,
                      considerToday: true)    // Oct 10, 2019 at 9:21 AM


Date.today().next(.monday)
            .next(.sunday)
            .next(.thursday)                  // Oct 31, 2019 at 9:21 AM

这是延期日期

extension Date {

  static func today() -> Date {
      return Date()
  }

  func next(_ weekday: Weekday, considerToday: Bool = false) -> Date {
    return get(.next,
               weekday,
               considerToday: considerToday)
  }

  func previous(_ weekday: Weekday, considerToday: Bool = false) -> Date {
    return get(.previous,
               weekday,
               considerToday: considerToday)
  }

  func get(_ direction: SearchDirection,
           _ weekDay: Weekday,
           considerToday consider: Bool = false) -> Date {

    let dayName = weekDay.rawValue

    let weekdaysName = getWeekDaysInEnglish().map { $0.lowercased() }

    assert(weekdaysName.contains(dayName), "weekday symbol should be in form \(weekdaysName)")

    let searchWeekdayIndex = weekdaysName.firstIndex(of: dayName)! + 1

    let calendar = Calendar(identifier: .gregorian)

    if consider && calendar.component(.weekday, from: self) == searchWeekdayIndex {
      return self
    }

    var nextDateComponent = calendar.dateComponents([.hour, .minute, .second], from: self)
    nextDateComponent.weekday = searchWeekdayIndex

    let date = calendar.nextDate(after: self,
                                 matching: nextDateComponent,
                                 matchingPolicy: .nextTime,
                                 direction: direction.calendarSearchDirection)

    return date!
  }

}

// MARK: Helper methods
extension Date {
  func getWeekDaysInEnglish() -> [String] {
    var calendar = Calendar(identifier: .gregorian)
    calendar.locale = Locale(identifier: "en_US_POSIX")
    return calendar.weekdaySymbols
  }

  enum Weekday: String {
    case monday, tuesday, wednesday, thursday, friday, saturday, sunday
  }

  enum SearchDirection {
    case next
    case previous

    var calendarSearchDirection: Calendar.SearchDirection {
      switch self {
      case .next:
        return .forward
      case .previous:
        return .backward
      }
    }
  }
}

---

您可以使用日历ISO8601，其中第一个工作日为星期一：

Swift 5.2或更高版本

extension Calendar {
    static let iso8601 = Calendar(identifier: .iso8601)
    static let iso8601UTC: Calendar = {
        var calendar = Calendar(identifier: .iso8601)
        calendar.timeZone = TimeZone(identifier: "UTC")!
        return calendar
    }()
}

---

---

作为日期计算机属性扩展实现：

extension Date {
    var mondayOfTheSameWeek: Date {
        Calendar.iso8601.dateComponents([.calendar, .yearForWeekOfYear, .weekOfYear], from: self).date!
    }
    var mondayOfTheSameWeekAtUTC: Date {
        Calendar.iso8601UTC.dateComponents([.calendar, .yearForWeekOfYear, .weekOfYear], from: self).date!
    }
}

---

添加到@Saneep应答

如果您想根据给定/当前日期获得准确的日期时间（假设您想将周一的dateTime->

23-05-2016 12:00:00

转换为

23-05-2016 05:35:17

），请尝试以下操作：

func convertDate(date: NSDate, toGivendate: NSDate) -> NSDate {
    let calendar = NSCalendar.currentCalendar()
    let comp = calendar.components([.Year, .Month, .Day, .Hour, .Minute, .Second], fromDate: toGivendate)
    let hour = comp.hour
    let minute = comp.minute
    let second = comp.second

    let dateComp = calendar.components([.Year, .Month, .Day], fromDate: date)
    let year = dateComp.year
    let month = dateComp.month
    let day = dateComp.day

    let components = NSDateComponents()
    components.year = year
    components.month = month
    components.day = day
    components.hour = hour
    components.minute = minute
    components.second = second

    let newConvertedDate = calendar.dateFromComponents(components)

    return newConvertedDate!
}

---

这是我创建的扩展，它首先查找星期天，然后添加一天

extension Date {  
    var startOfWeek: Date? {
        let gregorian = Calendar(identifier: .gregorian)
        guard let sunday = gregorian.date(from: gregorian.dateComponents([.yearForWeekOfYear, .weekOfYear], from: self)) else { return nil }
        return gregorian.date(byAdding: .day, value: 1, to: sunday)
    }
}

---

这里是的简化版本

用法：

Date().next(.monday)
Date().next(.monday, considerToday: true)
Date().next(.monday, direction: .backward)

分机：

public func next(_ weekday: Weekday,
                 direction: Calendar.SearchDirection = .forward,
                 considerToday: Bool = false) -> Date
{
    let calendar = Calendar(identifier: .gregorian)
    let components = DateComponents(weekday: weekday.rawValue)

    if considerToday &&
        calendar.component(.weekday, from: self) == weekday.rawValue
    {
        return self
    }

    return calendar.nextDate(after: self,
                             matching: components,
                             matchingPolicy: .nextTime,
                             direction: direction)!
}

public enum Weekday: Int {
    case sunday = 1, monday, tuesday, wednesday, thursday, friday, saturday
}

---

Swift 4解决方案

我已经根据我的要求计算出了，我已经找到了下面的日期

1. Today

2. Tomorrow 

3. This Week 

4. This Weekend 

5. Next Week 

6. Next Weekend

因此，我创建了

日期扩展

，以获取本周和下周的日期

代码

extension Date {

    func getWeekDates() -> (thisWeek:[Date],nextWeek:[Date]) {
        var tuple: (thisWeek:[Date],nextWeek:[Date])
        var arrThisWeek: [Date] = []
        for i in 0..<7 {
            arrThisWeek.append(Calendar.current.date(byAdding: .day, value: i, to: startOfWeek)!)
        }
        var arrNextWeek: [Date] = []
        for i in 1...7 {
            arrNextWeek.append(Calendar.current.date(byAdding: .day, value: i, to: arrThisWeek.last!)!)
        }
        tuple = (thisWeek: arrThisWeek,nextWeek: arrNextWeek)
        return tuple
    }

    var tomorrow: 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 startOfWeek: Date {
        let gregorian = Calendar(identifier: .gregorian)
        let sunday = gregorian.date(from: gregorian.dateComponents([.yearForWeekOfYear, .weekOfYear], from: self))
        return gregorian.date(byAdding: .day, value: 1, to: sunday!)!
    }

    func toDate(format: String) -> String {
        let formatter = DateFormatter()
        formatter.dateFormat = format
        return formatter.string(from: self)
    }
}

您可以根据需要修改扩展名

谢谢简单代码（请记住更好地注意选项）：

---

您可以使用日历ISO8601，其中第一个工作日是星期一，并且不要将第一个工作日更改为1（星期日），让calendar=NSCalendar（calendarIdentifier:NSCalendarIdentifierISO8601）！你的问题我不清楚。如果您设置了

calendar.firstWeekday=1

，那么星期天被定义为一周的第一天，因此您的结果是可以预期的。我如何更改以获得本周结束时的星期天（本周为11月1日）？现在我可以使用get（.Previous，“Monday”）获取当前周的星期一，并使用get（.Next，“Sunday”获取当前周的星期一，considerToday:true）以成功获取当前周的星期日。如果一周从周一开始到周日结束。这是我需要的，但我也需要得到下周一和下周日。所以我可以用你的get（.Next，“Monday”）来获取下周的周一，但我无法获取下周的周日。可以这样做吗？为了得到准确的时间，不仅仅是上午12:00，请查看我的答案。如果我有

2018-04-02

并询问前一个星期日，它会给我

2018-03-25

而不是

2018-04-01

。你如何看待日期？登录到XCode控制台？查看时区，可能是因为它为原始时区提供了正确的日期，而不是使用.Nice扩展名打印的时区，但是添加的值不应该是2，因为

.firstWeekday

？如果我使用的是值1，它会传递星期天的日期…

返回gregorian.date（通过添加：.day，值2，到：Sunday）

我不确定为什么会得到星期天。我刚试过，得到了一个星期一，我想你应该使用gregorian.firstWeekday，而不是1或2。问题是：如果是星期天，这个扩展将返回明天的日期。如果你认为星期天是最后一天，那么你应该得到前一个星期一，而不是下一个星期一。完美的答案，带时区的小修正<代码>变量comp:DateComponents=Calendar（标识符：.iso8601）。DateComponents（[.yearForWeekOfYear，.weekOfYear]，from:Date（））comp.timeZone=timeZone（secondsFromGMT:0）让mondayDate=Calendar（标识符：.iso8601）。日期（from:comp）！打印（“星期一\（星期一日期）”如果

WeekDay

不是以

Sunday

开始的，它是否正确？@无论系统首选项如何，它都可以工作，但您不能更改枚举。并非每个日期都有24小时

1. Today

2. Tomorrow 

3. This Week 

4. This Weekend 

5. Next Week 

6. Next Weekend

extension Date {

    func getWeekDates() -> (thisWeek:[Date],nextWeek:[Date]) {
        var tuple: (thisWeek:[Date],nextWeek:[Date])
        var arrThisWeek: [Date] = []
        for i in 0..<7 {
            arrThisWeek.append(Calendar.current.date(byAdding: .day, value: i, to: startOfWeek)!)
        }
        var arrNextWeek: [Date] = []
        for i in 1...7 {
            arrNextWeek.append(Calendar.current.date(byAdding: .day, value: i, to: arrThisWeek.last!)!)
        }
        tuple = (thisWeek: arrThisWeek,nextWeek: arrNextWeek)
        return tuple
    }

    var tomorrow: 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 startOfWeek: Date {
        let gregorian = Calendar(identifier: .gregorian)
        let sunday = gregorian.date(from: gregorian.dateComponents([.yearForWeekOfYear, .weekOfYear], from: self))
        return gregorian.date(byAdding: .day, value: 1, to: sunday!)!
    }

    func toDate(format: String) -> String {
        let formatter = DateFormatter()
        formatter.dateFormat = format
        return formatter.string(from: self)
    }
}

let arrWeekDates = Date().getWeekDates() // Get dates of Current and Next week.
let dateFormat = "MMM dd" // Date format
let thisMon = arrWeekDates.thisWeek.first!.toDate(format: dateFormat)
let thisSat = arrWeekDates.thisWeek[arrWeekDates.thisWeek.count - 2].toDate(format: dateFormat)
let thisSun = arrWeekDates.thisWeek[arrWeekDates.thisWeek.count - 1].toDate(format: dateFormat)

let nextMon = arrWeekDates.nextWeek.first!.toDate(format: dateFormat)
let nextSat = arrWeekDates.nextWeek[arrWeekDates.nextWeek.count - 2].toDate(format: dateFormat)
let nextSun = arrWeekDates.nextWeek[arrWeekDates.nextWeek.count - 1].toDate(format: dateFormat)

print("Today: \(Date().toDate(format: dateFormat))") // Sep 26
print("Tomorrow: \(Date().tomorrow.toDate(format: dateFormat))") // Sep 27
print("This Week: \(thisMon) - \(thisSun)") // Sep 24 - Sep 30
print("This Weekend: \(thisSat) - \(thisSun)") // Sep 29 - Sep 30
print("Next Week: \(nextMon) - \(nextSun)") // Oct 01 - Oct 07
print("Next Weekend: \(nextSat) - \(nextSun)") // Oct 06 - Oct 07

let now = Date()

var calendar = Calendar(identifier: .gregorian)

let timeZone = TimeZone(identifier: "UTC")!

let desiredWeekDay = 2

let weekDay = calendar.component(.weekday, from: now)
var weekDayDate = calendar.date(bySetting: .weekday, value: desiredWeekDay, of: now)!

/// Swift will give back the closest day matching the value above so we need to manipulate it to be always included at cuurent week.
if weekDayDate > now, weekDay > desiredWeekDay {
    weekDayDate = weekDayDate - 7*24*60*60
}

print(weekDayDate)