I have a UIDatePicker and set minimum date and minute interval, however there is a visual bug when selecting date. Minimum minute is selectable but appears with the non-selectable grey color.
My code:
#IBOutlet weak var datePicker: UIDatePicker!
override func viewDidLoad() {
super.viewDidLoad()
datePicker.preferredDatePickerStyle = .wheels
datePicker.minuteInterval = 5
datePicker.minimumDate = Date(timeIntervalSinceNow: 7200) // 7200 is equal to 2 hours
}
Screenshot:
I think the date picker is somewhat confused because the minimum date isn't a multiple of five minutes. For example, if you opened the app at 12:34, then Date(timeIntervalSinceNow: 7200) is going to be 14:34, and that doesn't correspond to any date on the date picker, which might be why it is behaving weirdly like this. I don't think this intended though.
Anyway, if you always give it a date that is a multiple of 5 minutes (or whatever minuteInterval you have), then it will work as expected.
From your description of the desired behaviour, it seems like you want to find the next five minute mark if the current minute component is not divisible by 5, then add 2 hours. You can do:
let calendar = Calendar.current
let now = Date()
let currentMinute = calendar.component(.minute, from: now)
let mod = currentMinute % 5
let minutesUntilNextMultipleOf5 = mod == 0 ? mod : 5 - mod
let minDate = calendar.date(byAdding:
DateComponents(hour: 2, minute: minutesUntilNextMultipleOf5),
to: now)
datePicker.minimumDate = minDate
Related
Using date format "EEEE:dd:MMM:HH:mm" returns the correct date and time, however, the day of the week is incorrect. For example a 750 nautical mile voyage conducted at 7.5 knots will take 100 hours. If I use my code to calculate the arrival time using a start of, say, Friday 1 Nov at 12:00 it returns Sunday 5 Nov at 16:00. Time and date are correct but day of the week is not. Should be Tuesday.
#IBAction func Calculate(_ sender: UIButton) {
let userCalendar = Calendar.current
let dateMakerFormatter = DateFormatter()
dateMakerFormatter.dateFormat = "EEEE:dd:MMM:HH:mm"
let distance = (Distance.text! as NSString).floatValue
let speed = (GndSpd.text! as NSString).floatValue
let calcDT = ((distance / speed) * 3600)
if var date = dateMakerFormatter.date(from: (DTG.text!)) {
date = dateMakerFormatter.date(from: (DTG.text!))!
var timeAdj = DateComponents()
timeAdj.second = Int(calcDT)
if var adj = userCalendar.date(byAdding: timeAdj, to: date) {
adj = userCalendar.date(byAdding: timeAdj, to: date)!
CalcDTG.text = dateMakerFormatter.string(from: adj)
}
}
}
You should use d for Day, not D
dateMakerFormatter.dateFormat = "EEEE:dd:MMM:HH:mm"
DateFormatter
You can't say the day of the week is incorrect when you're not giving a year.
The date formatter seems to ignore the day of the week when creating a date:
let dateMakerFormatter = DateFormatter()
dateMakerFormatter.dateFormat = "EEEE:dd:MMM:HH:mm"
let date = dateMakerFormatter.date(from: "Friday:01:Nov:12:00")!
print(date) -> 2000-11-01 12:00:00 +0000
print(dateMakerFormatter.string(from: date)) -> Wednesday:01:Nov:12:00
Hey presto, you're now in the year 2000, where 5 November did fall on a Sunday.
The important takeaway you need is that you should never, ever, ever, use strings to pass around date values in your code. Use Date. If you're getting a date from an API response, change it to a date on ingestion. If you're getting one from user entry, use a date picker or other control. If you're getting one from a string the user is typing in, I'd politely suggest you're making unnecessary work for yourself, but do make sure you fill in all the details the user doesn't give you.
I want to convert my variable for hours which is an integer into a 24 hour time system (for example, if it is 01:05:13 PM, hours will be saved as 13, minutes will be saved as 5, and seconds will be saved as 13) so that I can use it for some math later in my code to fid some differences on a scheduling app I am working on. This is my first app and I couldn't find an answer to this anywhere else so thanks for your help! Another way this code could work is getting the amount in seconds since the day has begun, if anyone knows how to do that, it would be greatly appreciated!
This is my function for getting the time and saving it as three different integers for hours, seconds, and minutes:
#IBAction func setTime() {
var date = NSDate()
//pickTimes()
var calendar = NSCalendar.current
calendar.timeZone = TimeZone(identifier: "UTC")!
var currentHour = calendar.component(.hour, from: date as Date) + 5
let currentMinutes = calendar.component(.minute, from: date as Date)
let currentSeconds = calendar.component(.second, from: date as Date)
timeText.text = ("\(currentHour):\(currentMinutes):\(currentSeconds)")
}
calendar.component(.hour, from: someDate) already gives you the time of day in 24 hour time so there's nothing else to do to solve your question.
Not sure why you are adding 5 to the hour. You set the timezone to UTC so the date will be treated as the UTC timezone. Then you add 5 to that result. That's kind of strange. If you just want the current hour in the user's locale timezone, don't change the calendar's timezone and don't add 5 to the hour.
Don't use NSDate or NSCalendar. This is Swift. Use Date and Calendar.
Updated code:
#IBAction func setTime() {
var date = Date()
//pickTimes()
var calendar = Calendar.current
var currentHour = calendar.component(.hour, from: date)
let currentMinutes = calendar.component(.minute, from: date)
let currentSeconds = calendar.component(.second, from: date)
timeText.text = ("\(currentHour):\(currentMinutes):\(currentSeconds)")
}
But it would be simpler to use a DateFormatter and set the timeStyle to .medium or maybe .long and format Date() into a string. This will give a properly localized time string.
i am completely new in iPhone app development. i am trying to find difference between min_date and max_date in hours. and wants save its value in textfield. Kindly Provide me complete code to find out difference between both of dates. e.g. if min_date: 12/07/1989, 12:00 am and max_date: 13/07/1989,12:00 am , then total hours will be 24 hours. Please provide me code in swift 3.0.
First, use timeIntervalSince to get the difference in seconds:
let timeInterval = max_date.timeIntervalSince(min_date)
Then you can do some maths to calculate the number of hours
let hours = timeInterval / 60 / 60
You can choose to floor or ceiling this number, depending on your requirements.
let previousDate = ...
let now = Date()
let formatter = DateComponentsFormatter()
formatter.unitsStyle = .full
formatter.allowedUnits = [.month, .day, .hour, .minute, .second]
formatter.maximumUnitCount = 2 // often, you don't care about seconds
if the elapsed time is in months, so you'll set max unit to whatever is
appropriate in your case
let string = formatter.string(from: previousDate, to: now)
let minDate = Date() // your min date
let maxDate = Date() // your max date
let components = Calendar.current.dateComponents([.hour], from: minDate, to: maxDate)
It's the most flexible method for search difference between two dates. You can use other components to search for months, days, years etc.
I have 2 TimeIntervals, which just represent date-agnostic times of day (e.g. 8:00 AM and 5:00 PM). So 0 represents exactly midnight, in this case, and 29,040 represents 8:04 AM. I want to check if the phone's time of day is between the two TimeIntervals.
I found a few similar Stack Overflow questions, but none of them really dealt with TimeIntervals. It seems like just using start <= Date().timeIntervalSinceReferenceDate <= end or something wouldn't work, because it would return a huge value.
What's the best way to handle this type of situation in Swift 3?
Edit: To clarify, I don't need to worry about things like daylight savings. As an example, assume that the user only wants certain things in the app to happen between the hours of X and Y, where X and Y are given to me as TimeInterval values since midnight. So it should be sufficient to check if the phone's TimeInterval since midnight on a typical day is between X and Y before completing the action.
Date().timeIntervalSinceReferenceDate returns the number of seconds since Jan 1, 2000 so no doubt it's a huge number.
It's inadvisable to store time as seconds since midnight due to this naggy little thing called Daylight Saving Time. Every year, different countries do it on different days and on different hours. For example, even though Britain and France change their clock on the same day (March 26, 2017), one makes the shift from 1AM to 2AM, the other goes from 2AM to 3AM. That's very easy to make for a mess!
Use DateComponents instead:
let calendar = Calendar.current
let startTimeComponent = DateComponents(calendar: calendar, hour: 8)
let endTimeComponent = DateComponents(calendar: calendar, hour: 17, minute: 30)
let now = Date()
let startOfToday = calendar.startOfDay(for: now)
let startTime = calendar.date(byAdding: startTimeComponent, to: startOfToday)!
let endTime = calendar.date(byAdding: endTimeComponent, to: startOfToday)!
if startTime <= now && now <= endTime {
print("between 8 AM and 5:30 PM")
} else {
print("not between 8 AM and 5:30 PM")
}
I ended up using DateComponents to calculate a TimeInterval.
let components = Calendar.current.dateComponents(
[.hour, .minute, .second], from: Date())
guard let seconds = components.second,
let minutes = components.minute,
let hours = components.hour else
{
return false
}
let currentTime = Double(seconds + minutes * 60 + hours * 60 * 60)
return startTime <= currentTime && currentTime <= endTime
I am trying to find the time (in seconds) between now and a specific time during that day e.g 9:00 AM and if the time now is past this specified time in the day, I would want the time between now and that set time in the next day.
My ultimate goal is to run a function at every hour from 8:00 AM to 5:00 PM, while the application is not open/ in background. If there is a better way to do this without using a timer with an interval of 24 hours then I would really appreciate some suggestions.
For adding an hour to the current time. Use the below extension
extension Date {
func addHours(_ hours: Int) -> Date {
let seconds: TimeInterval = Double(hours) * 60 * 60
let newDate: Date = self.addingTimeInterval(seconds)
return newDate
}
}
call this function as Date().addHours(1)
To get specific time of current date
func getDateFromHour(hour: Int) -> Date {
let date = Date()
let calendar = Calendar.current
et componentsCurrent = calendar.dateComponents([.year, .month, .day], from: date)
var components = DateComponents()
components.hour = hour
components.minute = 0
components.second = 0
components.month = componentsCurrent.month
components.day = componentsCurrent.day
components.year = componentsCurrent.year
return calendar.date(from: components)!
}
Note: you should use 24-hour clock while passing the parameter hour.