Date extension that help us to get day of week, day number of week, date list as date etc.. (between two dates)

DateHelper.swift

//  DateHelper.swift
//
//  Created by Coder ACJHP on 2.08.2018.
//  Copyright © 2018 Coder ACJHP. All rights reserved.
//

import Foundation

extension Date {
    
    func dayNumberOfWeek() -> Int? {
        return Calendar.current.dateComponents([.weekday], from: self).weekday
    }
    
    func dayOfWeek() -> String? {
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "EEEE"
        return dateFormatter.string(from: self).capitalized
    }
    
    public func getDateListBetweenTwoDates(fromDate: String = "2017-01-01", toDate: String = "2018-01-01") -> [Date] {
        var dateList : [Date] = []
        var dateFrom =  Date() // First date
        var dateTo = Date()   // Last date
        
        let fmt = DateFormatter()
        fmt.dateFormat = "yyyy-MM-dd"
        dateFrom = fmt.date(from: fromDate)!
        dateTo = fmt.date(from: toDate)!
        
        while dateFrom < dateTo {
            dateList.append(dateFrom)
            dateFrom = Calendar.current.date(byAdding: .day, value: 1, to: dateFrom)!
        }
        return dateList
    }
    
    public func getDayOfWeekListBetweenToDates(fromDate: String = "2017-01-01", toDate: String = "2018-01-01") -> [String] {
        var dayOfWeekList : [String] = []
        var dateFrom =  Date() // First date
        var dateTo = Date()   // Last date
        
        let fmt = DateFormatter()
        fmt.dateFormat = "yyyy-MM-dd"
        dateFrom = fmt.date(from: fromDate)!
        dateTo = fmt.date(from: toDate)!
        
        while dateFrom < dateTo {
            dayOfWeekList.append(dateFrom.dayOfWeek()!)
            dateFrom = Calendar.current.date(byAdding: .day, value: 1, to: dateFrom)!
        }
        return dayOfWeekList
    }
    
    public func getNumberOfWeekListBetweenToDates(fromDate: String = "2017-01-01", toDate: String = "2018-01-01") -> [Int] {
        var numberOfWeekList : [Int] = []
        var dateFrom =  Date() // First date
        var dateTo = Date()   // Last date
        
        let fmt = DateFormatter()
        fmt.dateFormat = "yyyy-MM-dd"
        dateFrom = fmt.date(from: fromDate)!
        dateTo = fmt.date(from: toDate)!
        
        while dateFrom < dateTo {
            numberOfWeekList.append(dateFrom.dayNumberOfWeek()!)
            dateFrom = Calendar.current.date(byAdding: .day, value: 1, to: dateFrom)!
        }
        return numberOfWeekList
    }
    
    func arrayOfDatesWithPattern(pattern: String = "EEE") -> NSArray {
        
        let numberOfDays: Int = 31
        let startDate = Date()
        let formatter: DateFormatter = DateFormatter()
        formatter.dateFormat = pattern
        let calendar = Calendar.current
        var offset = DateComponents()
        var dates: [Any] = [formatter.string(from: startDate)]
        
        for i in 1..<numberOfDays {
            offset.day = i
            let nextDay: Date? = calendar.date(byAdding: offset, to: startDate)
            let nextDayString = formatter.string(from: nextDay!)
            dates.append(nextDayString)
        }
        return dates as NSArray
    }
}