UIDate Picker

just set the maximum date ; you may also set minimum date on the instance (IBOutlet) of the UIDatePicker.

datePicker.minimumDate = Date()     // Today
datePicker.maximumDate = Date() + 14 * 86400 // 14 days

How would I get it so that it doesn't show any of the dates before the current day and doesn't show any of the dates after the two weeks?

I don't think it is possible (the design as a Rolodex would look bad if you had for instance just 2 days to display), unless you create a specific UIDatePicker by sublassing it (or create a custom from a UIPicker) ; but that's not worth it.

What you have here is that if you ask for a date after the maximum, it reverts to the maximum. So, it is impossible to set a date beyong the limit. Isn't that enough ?

How would I do it if I create a custom from UIPicker and what would the code look like?

I don't think this is a good idea.

But you would create a picker with 3 components :

- day

- hour

- minutes. // If no minutes, just 2 components

    @IBOutlet weak var picker: UIPickerView!

    // MARK:- Picker Data Source Methods

    func numberOfComponents(in pickerView: UIPickerView) -> Int {

        return 3
    }

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {

        switch component {
        case 0 : return 15 // From today to today + 14
        case 1: return 24     // 00 to 23
        case 2: return 12     // If you want to show every 5 minutes
        default: return 0
        }
    }

    // MARK:- Picker Delegate Methods

    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {

        let today = Date()
        let formatter = DateFormatter()
        formatter.dateFormat = "EEE. MMM dd"     // Sat. Aug 18
        switch component {
        case 0 :
          let currentDay = today + row * 86400
          return  formatter.string(from: currentDay)
        case 1:
            return String(format: "%02d", row)
        case 2:
            let minutes = 5 * row
            return String(format: "%02d", minutes)
        default: return ""
        }
    }

Do whatever you need when selected:

    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
      
        let dayOfWPicked = picker.selectedRow(inComponent: 0)
        let monthPicked = picker.selectedRow(inComponent: 1)
        let dayPicked = picker.selectedRow(inComponent: 2)
         }

     // use these 3 Int value as needed

   }

let currentDay = today + row * 86400

Please please please don’t hard code numbers like this. Not every day has 86400 seconds, and when your app hits one of these days it will fail is mysterious and hard-to-reproduce ways.

To go from day to day reliably you must us

Calendar

date(byAdding:to:)

formatter.dateFormat = "EEE. MMM dd"     // Sat. Aug 18

You also shouldn’t hard code date formats like this. The user display of dates varies wildly by locale. The correct way to do this is with code like this:

let df = DateFormatter()
df.setLocalizedDateFormatFromTemplate("EEE MMM dd")
// "Mon, Aug 20" in en_US
// "Mon 20 Aug" in en_GB
// "lun. 20 août" in fr_FR

The system will then ensure that all all of your date components are shown, in the right order, with the right separators. It may even add date components, depending on the locale and components you requested.

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"

Thanks. You're right (as usual) even though I find date manipulation a bit tedious (or needing practice probably).

So better code would be

datePicker.minimumDate = Date()     // Today
let df = DateFormatter()
df.setLocalizedDateFormatFromTemplate("EEE MMM dd")
let calendar = Calendar.current
let today = Date()
let comps = DateComponents(day: 3)
datePicker.maximumDate = calendar.date(byAdding: comps, to: today)

So better code would be

Right.

My only other comment is that this:

let today = Date()

always seems suspect to me, because the

Date

today

• I work primarily in date components, only converting to

  Date

  values when the API requires it.

• When that’s required, I pin the ‘time’ parts of the date components to midday (that is, set

  .hours

  to 12,

  .minutes

  to 0, and

  .seconds

  to 0) so I’m always working with midday values.

This last part prevents me from accidentally hitting a time discontinuity.

IMPORTANT Using midnight values is very bad, because some time zones do their daylight savings time change at midnight! If you ever get a calendar-related bug report from someone in Brazil that’s having problems around spring or autumn, you’ve likely hit this problem.

Share and Enjoy
—
Quinn “The Eskimo!”
Apple Developer Relations, Developer Technical Support, Core OS/Hardware

let myEmail = "eskimo" + "1" + "@apple.com"