Building an app that issues queueing system tickets. The user checks the branch he will reserve his ticket in and issues a ticket with a certain delay time. The delay time is the time he will need to reach the branch.
The queueing system API branches database has the opening and closing time fields of the branch in string format as "9:00" and "17:00". Also API has a boolean field i use it if branch is closed or open so i check that boolean to not issue tickets if branch status is closed.
The issue is when the branch is open the user will issue a ticket with a certain delay time. What i need to do is to calculate:
var branchClosingTime = "17:00"
var delay = 3000 //sec
var timeNow = Date().TimeIntervalSince1970
if (timeNow + delay) < branchClosingTime {
print("Issue ticket")
} else {
print("Don't issue ticket")
}
By this calculation i will check if he didn't by pass the branch closing time. I have the algorithm in mind but i really don't know how this could be done. I played a little bit in the xcode playground converting dates to unix timestamps but i don't know how to convert this closing time string to a unix timestamp and compare.
You can parse out the contents of the string using:
let dateString = "20:34"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "HH:mm"
if let date = dateFormatter.date(from: dateString) {
let calendar = Calendar.current
let components = calendar.dateComponents([.hour,.minute], from: date)
print(components.hour!)
print(components.minute!)
}
The Calendar class has routines that should help you figure out what date (relative to right now) that the string represents. I don't know, for example, if your "17:00" means today, or the next occurrence of 17:00... but the calendar class has routines to help you figure it out.
Thanks to #Scott's advices i was able to solve my issue and here is how it was done.
var orderTime: TimeInterval = 1494520200 - 7200 // -7200 sec to adabt to my time zone
var delay: TimeInterval = 2000 //sec
var orderDate = Date(timeIntervalSince1970: orderTime) // "May 11, 2017, 4:30 PM"
var orderDateWithDelay = orderDate + delay //"May 11, 2017, 5:03 PM"
let dateString = "17:00"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "HH:mm"
if let date = dateFormatter.date(from: dateString) {
let calendar = Calendar.current
let components = calendar.dateComponents([.hour,.minute], from: date)
let closeDate = calendar.nextDate(after: orderDate, matching: components, matchingPolicy: .nextTime, repeatedTimePolicy: .first, direction: .forward) //"May 11, 2017, 5:00 PM"
if closeDate!.compare(orderDateWithDelay) == .orderedDescending
{
print("Close date after order date")
print("Issue ticket")
} else if closeDate!.compare(orderDateWithDelay) == .orderedAscending {
print("Close date before order date")
print("Don't issue ticket")
}
}
Related
I'm trying to get the correct time interval between two times that span two days (Overnight). Here is my code successfully printing out the difference between two times - however for my use case I need the ability to span overnight, how might I do this?
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "HH:mm"
//This time represents (23:00, Aug 07) for example
let date1 = dateFormatter.date(from: "23:00")!
//This time represents (06:00, Aug 08) for example
let date2 = dateFormatter.date(from: "06:00")!
let elapsedTime = date2.timeIntervalSince(date1)
print(abs(elapsedTime)/60/60)
//prints 17.0
My desired result is a print out of 7, as that is the amount of hours between 23:00, Aug 7 and 06:00, Aug 8 - My current code is correctly showing me the interval between those two times (as if they were from the same day) but I am trying to work out how to account for when those times overlap two days. Any help would be much appreciated.
UPDATE:
To give a more complete picture I have an object that has a start and and end date represented by a string:
Activity(startTime: "23:00", endTime: "06:00")
I use some functions to turn those strings into dates:
func startDate(startTime: String) -> Date {
let currentDate = Date().string(format: "dd-MM-yyyy")
let myStartingDate = "\(currentDate) \(startTime)"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd-MM-yyyy HH:mm"
let startDate = dateFormatter.date(from: myStartingDate)
return startDate!
}
func endDate(endTime: String) -> Date {
let currentDate = Date().string(format: "dd-MM-yyyy")
let myEndingDate = "\(currentDate) \(endTime)"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "dd-MM-yyyy HH:mm"
let endDate = dateFormatter.date(from: myEndingDate)
return endDate!
}
So my more complete workings look more like this:
func calculateTimeInterval(activity: Activity) {
let startHourDate = self.startDate(startTime: activity.startTime)
let endHourDate = self.endDate(endTime: activity.endTime)
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "HH:mm"
//This time represents (23:00, Aug 07) for example
let date1 = startHourDate!
//This time represents (06:00, Aug 08) for example
let date2 = endHourDate!
let elapsedTime = date2.timeIntervalSince(date1)
print(abs(elapsedTime)/60/60)
}
//prints 17.0
Without a date part the only way to determine if the end time is past midnight is if the end time is less than the start time. If so your code can be changed to
var elapsedTime = date2.timeIntervalSince(date1)
if elapsedTime < 0 {
let date3 = date2 + 60 * 60 * 24
elapsedTime = date3.timeIntervalSince(date1)
}
print(elapsedTime/60/60)
You can write an Extension to Date like this:
extension Date {
func hours(from date: Date) -> Int {
return Calendar.current.dateComponents([.hour], from: date).hour ?? 0
}
}
And just use it on any Date directly. This way you don't need DateFormatter at all. Hope this helps!
I have a date in string format, "yyyy-MM-dd" and would like to return an array of the difference in dates in that same format from today.
For example, the given date is "2019-06-29", and today's date is 2019-06-25. The returned array would contain: ["2019-06-25", "2019-06-26", "2019-06-27", "2019-06-28", "2019-06-29"].
The method I am trying to write needs to also work cross-months/years. Is something like this possible in Swift?
What I have tried: calculating the difference in dates numerically (difference of days) and adding a day to the given date until it reaches today's date. This is what brought on the issue of exceeding 30/31 days and not moving to the next months/exceeding 2019-12-31 and not moving to 2020. Surely there is a simpler concise way to achieve this result without having to write that date logic manually?
extension Formatter {
static let date: DateFormatter = {
let dateFormatter = DateFormatter()
dateFormatter.calendar = Calendar(identifier: .iso8601)
dateFormatter.locale = Locale(identifier: "en_US_POSIX")
dateFormatter.dateFormat = "yyyy-MM-dd"
return dateFormatter
}()
}
extension Date {
var noon: Date {
return Calendar.current.date(bySettingHour: 12, minute: 0, second: 0, of: self)!
}
}
func dates(for date: String) -> [String] {
// For calendrical calculations you should use noon time
// So lets get endDate's noon time
guard let endDate = Formatter.date.date(from: date)?.noon else { return [] }
// then lets get today's noon time
var date = Date().noon
var dates: [String] = []
// while date is less than or equal to endDate
while date <= endDate {
// add the formatted date to the array
dates.append( Formatter.date.string(from: date))
// increment the date by one day
date = Calendar.current.date(byAdding: .day, value: 1, to: date)!
}
return dates
}
dates(for: "2019-06-29") // ["2019-06-25", "2019-06-26", "2019-06-27", "2019-06-28", "2019-06-29"]
I creating an itinerary generation app where the user is required to enter the dates of his/her trip. The only problem is, using UIDatePicker the dates are always given as the current time for a given day/month/year.
In a separate file I've extended Date class to try and write a simple method that will return midnight for a given date.
First I tried
var midnight:Date{
let cal = Calendar(identifier: .gregorian)
return cal.startOfDay(for: self)
}
However this always gave me either 04:00 or 05:00 depending on daylights savings, which gave me the idea that I should simply remove 4 or 5 hours depending on daylight savings, and so I created the following methods:
var timezone:TimeZone{
return TimeZone.current
}
///Returns the first instance of the date, e.g. 2018-02-26 00:00:00
var trueMidnight:Date{
let cal = Calendar(identifier: .gregorian)
let midnight = cal.startOfDay(for: self)
let secondsFromGMT = TimeZone.current.secondsFromGMT()
print("Daylight savings? \(daylightSavings)")
return midnight.addingTimeInterval(Double(secondsFromGMT))
}
///If this var returns true, then daylight savings time is active and an hour of daylight is gained (during the summer).
var isDaylightSavings:Bool{
return timezone.daylightSavingTimeOffset(for: self) == 0 ? false : true
}
var daylightSavings:Double{
return isDaylightSavings ? 3600.0 : 0.0
}
However these methods sometimes return midnight, 23:00, or even 22:00 the previous day.
I'm a relatively inexperienced programmer so I feel like I'm lacking a basic understanding for the date class or missing a large concept. Why is it so difficult for me to simply find midnight on a given date?
I even forsook the idea of returning midnight and tried to just find noon on a given day with the code:
var noon:Date{
let gregorian = Calendar(identifier: .gregorian)
var components = gregorian.dateComponents([.year, .month, .day, .hour, .minute, .second], from: self)
components.hour = 12
components.minute = 0
components.second = 0
return gregorian.date(from: components)!
}
But this returns 16:00 or 17:00 as opposed to noon. Any help would be appreciated.
When you print a date, it is printed in UTC time. So when you print your Dates, they differ from your local time by 4/5 hours.
If you use the following code instead
print(yourDate.description(with: .current))
Where yourDate is your date, it will be in the correct time zone.
You're confused.
If you use
print(Date())
You will get a date in UTC. If you're in the UTC+5 time zone, that date will be 5 hours greater than your local time. Thus if you try to display midnight local time in UTC, it will show up as 5:00 AM in UTC.
Try this:
extension Date {
func localString(dateStyle: DateFormatter.Style = .medium,
timeStyle: DateFormatter.Style = .medium) -> String {
return DateFormatter.localizedString(
from: self,
dateStyle: dateStyle,
timeStyle: timeStyle)
}
var midnight:Date{
let cal = Calendar(identifier: .gregorian)
return cal.startOfDay(for: self)
}
}
print("Tonight at midnight is " + Date().midnight.localString())
That code uses a function localString() that takes advantage of a DateFormatter method localizedString(from:dateStyle:timeStyle:) that converts a Date to a string in the current locale (which includes the local time zone.
I suggest adding that extension to your apps.
Say time string value is "7:00 AM" call it reminder time.
Now all I need to do is compare this time with the current dates time say its "9:00 AM" if reminder time is later than current time - return true else false. This is the format "h:mm a" for date formatters.
Simple right? It should be but I have burned too much time on this. I can get hour and minute values but when the AM/PM is considered it gets harder.
I just want to compare two time values and determine if the first is later or after the second one. The date is always today or current date so I only care about the time part of the date. Of course you have to convert to dates to do the comparison but current date is easy to get however date from "7:00 AM" string does not seem to work right in comparisons.
Anyone have a function to do this?
Thanks.
the approach would be lets date the Date() object from your current time object so you will get
default date + your time = 2000-01-01 00:00:00 +your time (7.00 AM or 9.00 PM)
now we will get the current time from today only, in same format. (Only time)
it will be something like 3.56 PM
now again we will convert this 3.56 PM to Date() with default date as prev. so now we will have two date time object with same Date(2000-01-01) and respective times.
2000-01-01 7:00:00 => this will your 7.00 AM with default date
2000-01-01 15:56:00 => this will be current time with default date
now we will compare two date object.
Check the fiddle Fiddle
func CompareMyTimeInString(myTime:String)->Bool
{
// create the formatter - we are expecting only "hh:mm a" format
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "hh:mm a"
dateFormatter.locale = Locale.init(identifier: "en_GB")
// default date with my time
var dt_MyTime = dateFormatter.date(from: yourTime)!
// current time in same format as string "hh:mm a"
var currentTimString = dateFormatter.string(from: Date());
print("Current Time is - "+currentTimString);
// current time with default date.
var dt_CurrentTime = dateFormatter.date(from: currentTimString)!
// now just compare two date objects :)
return dt_MyTime > dt_CurrentTime;
}
// then call it like
var yourTime = "7.00 AM"
var isDue = CompareMyTimeInString(myTime:yourTime);
print(isDue);
My solution was as follows.
private func ReminderAfterCurrentTime(reminderTimeString: String) -> Bool {
//Compare the two time strings and if reminderTimeString is later than current time string
//return true since Reminder is after current time.
//Get the current date and time
let currentDateTime = Date()
// Create calendar object
let calendar = NSCalendar.current
// Get current date hour and minute values for comparison.
let currentHourValue = Int(calendar.component(.hour, from: currentDateTime))
let currentMinuteValue = Int(calendar.component(.minute, from: currentDateTime))
//Now get a date from the time string passed in so we can get just the hours and minutes to compare
let dateformatter = DateFormatter()
dateformatter.dateStyle = DateFormatter.Style.none
dateformatter.timeStyle = DateFormatter.Style.short
//Now get the date using formatter.
let reminderDateTime = dateformatter.date(from: reminderTimeString)
print("reminderDateTime = \(reminderDateTime)")
//Get reminder hour and minute for comparison.
let reminderHourValue = Int(calendar.component(.hour, from: reminderDateTime!))
let reminderMinuteValue = Int(calendar.component(.minute, from: reminderDateTime!))
print("currentHourValue = \(currentHourValue)")
print("currentMinuteValue = \(currentMinuteValue)")
print("reminderHourValue = \(reminderHourValue)")
print("reminderMinuteValue = \(reminderMinuteValue)")
//This works due to 24 hour clock. Thus AM/PM is already taken into account.
if currentHourValue < reminderHourValue {
return true
}
//Check for same hour then use minutes
if currentHourValue == reminderHourValue {
if currentMinuteValue < reminderMinuteValue {
return true
}
}
//Otherwise return false
return false
}
I'm trying to display the time of something being open based on what day it is. Something like this:
Opening Hours
**Monday: 8:00-17:00**
Tuesday: 8:00-17:00
Wednesday: 8:00-17:00
Thursday: 8:00-17:00
Friday: 8:00-17:00
Saturday: 8:00-13:00
Sunday: closed
Or simply display
Monday: 8:00-17:00
My assumption would be to use switch statements, but what would I need to do to find out what day it is?
Another solution could be:
import Foundation
let today = NSDate()
let dateFormatter = NSDateFormatter()
let currentDay = NSCalendar.currentCalendar().component(.Weekday, fromDate:today);
dateFormatter.dateFormat = "EEEE"
let dayOfWeekString = dateFormatter.stringFromDate(today)
switch currentDay
{
case 2,3,4,5:
print("\(dayOfWeekString): 8:00 - 17:00")
case 6:
print("\(dayOfWeekString): 8:00 - 13:00")
default:
print("\(dayOfWeekString): closed")
}
You can use component(_:fromDate:) to get the week day from the current date. That would look like:
let currentDay = NSCalendar.currentCalendar().component(.Weekday, fromDate:NSDate());
Based on the value you get for currentDay, you can provide the correct opening hours.
You can make use of NSCalendar to get the .Weekday unit as an integer (Sunday through Saturday as 1 ... 7 for the Gregorian calendar).
Given you know the day of the week represented as an Int, rather than using a switch statement, you could use a [Int: String] dictionary for the different opening hours.
let calendar = NSCalendar.currentCalendar()
let today = calendar.component(.Weekday, fromDate: NSDate())
// Gregorian calendar: sunday = 0, monday = 1, ...
let openingHours: [Int: String] = [1: "Sunday: closed", 2: "Monday: 8:00-17:00", 3: "Tuesday: 8:00-17:00"] // ...
print("Opening hours:\n\(openingHours[today] ?? "")")
/* Opening hours:
Monday: 8:00-17:00 */
Another alternative is to create a computed property extension to NSDate() that returns the current weekday as a String
extension NSDate {
var weekday : String {
let formatter = NSDateFormatter()
formatter.dateFormat = "EEEE"
return formatter.stringFromDate(self)
}
}
This can be readily used with a [String: String] dictionary for holding the set of weekday : opening hours:
/* example usage */
let openingHours: [String: String] =
["Sunday": "closed",
"Monday": "8:00-17:00",
"Tuesday": "8:00-17:00"] // ...
let today = NSDate().weekday
print("Opening hours:\n\(today): \(openingHours[today] ?? "")")
/* Opening hours:
Monday: 8:00-17:00 */
Rather than going with switch statements I would prefer a more generic solution. This is also a nice demonstration of leveraging tuples and type aliases for enhancing code expressiveness and readability.
typealias Time = (start: Int, end: Int)
// starting with Sunday
let openTimes: [Time] = [(0,0), (9,17), (9,17), (9,17), (9,17), (9,17), (9,12)]
let flags : NSCalendarUnit = [.Hour, .Weekday]
func isOpenAtTime(date: NSDate) -> Bool {
let time = NSCalendar.currentCalendar().components(flags, fromDate: date)
let openingHours = openTimes[time.weekday - 1]
let hour = time.hour
return hour >= openingHours.start && hour <= openingHours.end
}
You might want to handle a few edge cases as well, but you get the idea.
You could make this work with more granular time by using minutes instead of hours.