swift - saber - Cómo obtener la fecha del lunes de la semana actual en forma rápida

obtener fechas de una semana php

Question

Estoy tratando de obtener la fecha del lunes de la semana actual. Esto se trata como el primer día de la semana en mi vista de tabla. También necesito obtener el domingo de la semana actual. Esto se trata como el último día de la semana en mi vista de tabla.

Intento actual:

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

Answer 1

Aquí está la extensión que creé, primero encuentra el domingo y luego agrega un día

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)
    }
}

Answer 2

Aquí hay una versión simplificada de share de share .

Uso:

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

Extensión:

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
}

Answer 3

Escribí extensiones de fecha para obtener la fecha de ciertos días de la semana y aquí es lo fácil que es usar con Swift 4,

Date.today().next(.monday)                    // Feb 12, 2018 at 12:00 AM
Date.today().next(.sunday)                    //  Feb 11, 2018 at 12:00 AM


Date.today().previous(.sunday)                // Feb 4, 2018 at 12:00 AM
Date.today().previous(.monday)                // Feb 5, 2018 at 12:00 AM

Date.today().previous(.thursday)              // Feb 1, 2018 at 12:00 AM
Date.today().next(.thursday)                  // Feb 15, 2018 at 12:00 AM
Date.today().previous(.thursday,
                      considerToday: true)    // Feb 8, 2018 at 11:04 PM


Date.today().next(.monday)
            .next(.sunday)
            .next(.thursday)                  // Feb 22, 2018 at 12:00 AM

Y aquí está la extensión de fecha para eso,

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.index(of: dayName)! + 1

    let calendar = Calendar(identifier: .gregorian)

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

    var nextDateComponent = DateComponents()
    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
      }
    }
  }
}

Answer 4

Puede usar el calendario ISO8601 donde el primer día de la semana es el lunes:

Swift 3 o posterior

var mondaysDate: Date {
    return Calendar(identifier: .iso8601).date(from: Calendar(identifier: .iso8601).dateComponents([.yearForWeekOfYear, .weekOfYear], from: Date()))!
}

print(mondaysDate.description(with: .current))   // Monday, July 16, 2018 at 12:00:00 AM Brasilia Standard Time"

como una extensión:

extension Calendar {
    static let iso8601 = Calendar(identifier: .iso8601)
}

extension Date {
    var currentWeekMonday: Date {
        return Calendar.iso8601.date(from: Calendar.iso8601.dateComponents([.yearForWeekOfYear, .weekOfYear], from: self))!
    }
}

let currentWeekMonday = Date().currentWeekMonday
print(currentWeekMonday.description(with: .current)) // Monday, July 16, 2018 at 12:00:00 AM Brasilia Standard Time 

Answer 5

Tratar de usar:

calendar.firstWeekday = 2

Editar

Para ser más específico: NSCalendar.currentCalendar() devuelve el calendario del usuario. Según los documentos:

El calendario devuelto se forma a partir de la configuración de la configuración regional del sistema elegida por el usuario actual superpuesta con cualquier configuración personalizada que el usuario haya especificado en Preferencias del sistema.

Si quieres siempre el lunes como primer día, creo que deberías usar:

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

Answer 6

Además de la respuesta @Saneep

Si desea obtener la fecha y hora exactas según la fecha dada / actual (digamos que desea convertir la fecha y hora del lunes -> 23-05-2016 12:00:00 a 23-05-2016 05:35:17 ) intente esto :

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!
}

Answer 7

Solución Swift 4

He descubierto de acuerdo a mi requerimiento, donde he encontrado fechas para seguir.

1. Today

2. Tomorrow 

3. This Week 

4. This Weekend 

5. Next Week 

6. Next Weekend

Por lo tanto, he creado la Date Extension para obtener las fechas de la semana actual y la próxima semana .

CÓDIGO

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)
    }
}

USO:

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

Puede modificar la Extension según sus necesidades.

¡Gracias!