问题
I'm trying to get the start and end dates of the current month in dd/MM/yyyy format. I tried using extension as answered in this SO Question.But it seems like it's not what I want(the format is different and also it's giving me last month's last date and current month last but one date ). Can some one help me.
Extension Class:
extension Date {
func startOfMonth() -> Date? {
let comp: DateComponents = Calendar.current.dateComponents([.year, .month, .hour], from: Calendar.current.startOfDay(for: self))
return Calendar.current.date(from: comp)!
}
func endOfMonth() -> Date? {
var comp: DateComponents = Calendar.current.dateComponents([.month, .day, .hour], from: Calendar.current.startOfDay(for: self))
comp.month = 1
comp.day = -1
return Calendar.current.date(byAdding: comp, to: self.startOfMonth()!)
}
}
My Struct:
struct Constants{
// keys required for making a Login call (POST Method)
struct LoginKeys {
.....
}
struct RankingKeys {
static let DateFrom = String(describing: Date().startOfMonth()) //giving me 2016-11-30 16:00:00 +0000
static let DateTo = String(describing: Date().endOfMonth())
//2016-12-30 16:00:00 +0000
}
}
Expected Result:
DateFrom = "01/12/2016"
DateTo = "31/12/2016"
回答1:
You should write this simple code:
let dateFormatter = DateFormatter()
let date = Date()
dateFormatter.dateFormat = "dd-MM-yyyy"
For start Date:
let comp: DateComponents = Calendar.current.dateComponents([.year, .month], from: date)
let startOfMonth = Calendar.current.date(from: comp)!
print(dateFormatter.string(from: startOfMonth))
For end Date:
var comps2 = DateComponents()
comps2.month = 1
comps2.day = -1
let endOfMonth = Calendar.current.date(byAdding: comps2, to: startOfMonth)
print(dateFormatter.string(from: endOfMonth!))
回答2:
This is what I'm using. Pretty simple but it works.
extension Calendar {
func dayOfWeek(_ date: Date) -> Int {
var dayOfWeek = self.component(.weekday, from: date) + 1 - self.firstWeekday
if dayOfWeek <= 0 {
dayOfWeek += 7
}
return dayOfWeek
}
func startOfWeek(_ date: Date) -> Date {
return self.date(byAdding: DateComponents(day: -self.dayOfWeek(date) + 1), to: date)!
}
func endOfWeek(_ date: Date) -> Date {
return self.date(byAdding: DateComponents(day: 6), to: self.startOfWeek(date))!
}
func startOfMonth(_ date: Date) -> Date {
return self.date(from: self.dateComponents([.year, .month], from: date))!
}
func endOfMonth(_ date: Date) -> Date {
return self.date(byAdding: DateComponents(month: 1, day: -1), to: self.startOfMonth(date))!
}
func startOfQuarter(_ date: Date) -> Date {
let quarter = (self.component(.month, from: date) - 1) / 3 + 1
return self.date(from: DateComponents(year: self.component(.year, from: date), month: (quarter - 1) * 3 + 1))!
}
func endOfQuarter(_ date: Date) -> Date {
return self.date(byAdding: DateComponents(month: 3, day: -1), to: self.startOfQuarter(date))!
}
func startOfYear(_ date: Date) -> Date {
return self.date(from: self.dateComponents([.year], from: date))!
}
func endOfYear(_ date: Date) -> Date {
return self.date(from: DateComponents(year: self.component(.year, from: date), month: 12, day: 31))!
}
}
How to use
let calendar: Calendar = Calendar.current
let startDate = calendar.startOfMonth(Date())
print("startDate :: \(startDate)")
回答3:
With Swift 3 & iOS 10 the easiest way I found to do this is Calendar's dateInterval(of:for:):
guard let interval = calendar.dateInterval(of: .month, for: Date()) else { return }
Then use a date formatter to print the dates:
let formatter = DateFormatter()
formatter.dateFormat = "dd-MM-yyyy"
let dateText = formatter.string(from: interval.start)
回答4:
This Extension Gives you expected output as per you want
Here I return date
extension NSDate {
func startOfMonth() -> NSDate? {
guard
let cal: NSCalendar = NSCalendar.currentCalendar(),
let comp: NSDateComponents = cal.components([.Year, .Month], fromDate: self) else { return nil }
comp.to12pm()
let dateformattor = NSDateFormatter()
dateformattor.dateFormat = "yyyy-MM-dd"
dateformattor.timeZone = NSTimeZone.localTimeZone()
let dt2 = dateformattor.stringFromDate(cal.dateFromComponents(comp)!)
print(dt2)
dateformattor.dateFormat = "yyyy-MM-dd"
dateformattor.timeZone = NSTimeZone.init(abbreviation: "UTC")
return dateformattor.dateFromString(dt2)
}
func endOfMonth() -> NSDate? {
guard
let cal: NSCalendar = NSCalendar.currentCalendar(),
let comp: NSDateComponents = NSDateComponents() else { return nil }
comp.month = 1
comp.day = -1
comp.to12pm()
let dateformattor = NSDateFormatter()
dateformattor.dateFormat = "yyyy-MM-dd"
dateformattor.timeZone = NSTimeZone.localTimeZone()
let dt2 = dateformattor.stringFromDate(cal.dateByAddingComponents(comp, toDate: self.startOfMonth()!, options: [])!)
dateformattor.dateFormat = "yyyy-MM-dd"
dateformattor.timeZone = NSTimeZone.init(abbreviation: "UTC")
return dateformattor.dateFromString(dt2)
}
}
internal extension NSDateComponents {
func to12pm() {
self.hour = 12
self.minute = 0
self.second = 0
}
}
**OUTPUT :- **
Start Date of Month :- 2016-12-01 00:00:00 +0000
End Date of Month :- 2016-12-31 00:00:00 +0000
回答5:
For the sake of completeness, the API dateInterval(of:start:interval:for:) of Calendar assigns the start date and interval (in seconds) of the current month to the inout parameters.
The date formatter considers the current time zone.
let formatter = DateFormatter()
formatter.locale = Locale(identifier: "en_US_POSIX")
formatter.dateFormat = "dd/MM/yyyy"
var startDate = Date()
var interval = TimeInterval()
Calendar.current.dateInterval(of: .month, start: &startDate, interval: &interval, for: Date())
let endDate = Calendar.current.date(byAdding: .second, value: Int(interval) - 1, to: startDate)!
let fromDate = formatter.string(from: startDate)
let toDate = formatter.string(from: endDate)
print(fromDate, toDate)
来源：https://stackoverflow.com/questions/41216460/how-to-get-start-date-and-end-date-of-the-current-month-swift-3