I am trying to do some math calculations in Swift and getting a bit stuck.
Essentially we get paid every 4th Friday, and I want to do a calculation that based on today's date, works out how many days until our next Pay Day.
I've got a reference day of "28/03/2008",
In order to calculate the next 4th Friday of the month, you need a combination of the right DateComponents and Calendar.
// The 4th Friday at noon
let payDayComps = DateComponents(hour: 12, weekday: 6, weekdayOrdinal: 4)
// Given the current date, calculate the next 4th Friday at noon
let nextPayDay = Calendar.current.nextDate(after: Date(), matching: payDayComps, matchingPolicy: .nextTime)
You don't need a past reference date for this if your goal is to get the next 4th Friday based on today's date. Change the value of the after parameter if you need to calculate the 4th Friday based on some other specific date.
If this is run on the 4th Friday of a month then it will return today's date if run before noon and it will return the 4th Friday of the next month if run after noon. Change the hour value in payDayComps if you want different results (such as 0 for midnight).
To calculate the number of days until that next pay day you can do:
let daysToPayDay = Calendar.current.dateComponents([.day], from: Date(), to: nextPayDay).day!
Related
I'm working on fitness app where users selects the days he wants to exercise on.
When he opens the app I wanna shown him the current week where he can observe the days his training sessions are scheduled for.
If he is from the US i wanna show him a week starting from Sunday. For EU users it should start with Monday.
Is there any way to get the "current" week dates depending on user's location/geo? Taking into account what day does the week start with in appropriate location.
I tried to find a solution for your question. I think this should work:
// Define a function that returns the following seven dates, given a start date
func getWeekDates(of startDate: Date, with calender: Calendar) -> [Date] {
var weekDates: [Date] = []
for i in 0..<7 {
weekDates.append(calendar.date(byAdding: .day, value: i, to: startDate)!)
}
return weekDates
}
// This should automatically take the right calendar for the user's locale
// If you want to specify the day weeks start with manually, choose .gregorian or .iso8601:
// .gregorian starts on Sunday, .iso8601 starts on Monday
let calendar = Calendar.current
let startOfCurrentWeek = calendar.date(from: calendar.dateComponents([.yearForWeekOfYear, .weekOfYear], from: Date()))
let currentWeekDates = getWeekDates(of: startOfCurrentWeek!, with: calendar)
Hope this helps.
Use
Calendar.current.firstWeekday
If it returns 1, then Sunday is the first day of week
If it returns 2, then Monday is the first day of week.
You can test this by setting locale manually
var calendar = Calendar.current
calendar.locale = Locale(identifier: "en_GB")
print("\(calendar.locale!) starts on day \(calendar.firstWeekday)")
// en_GB starts on day 2
calendar.locale = Locale(identifier: "en_US")
print("\(calendar.locale!) starts on day \(calendar.firstWeekday)")
So I have a program which I need to ask a user for a date and time. But that date has to either be in the future or the the very far past. And I have tried a UIDatePicker but have found out that a date picker isn't the best way to tend to this sort of problem because it requires a lot of scrolling, and the it doesn't load past a certain date for some reason. I was thinking of a UIPickerView that asks for Year, Month, Day, and Time. But I don't know how to do it because lets say that the month is September there is only 30 days so then how can I stop the user from selecting 31. So if anyone can help me that would be amazing. And if you have any questions or need for code just ask. Oh and by the way I would like it in a date format where I can compare it to other date.
Given the year and month, you can calculate the array of possible day values to be supplied to your picker like so:
let calendar = Calendar.current
let components = DateComponents(year: year, month: month, day: 1)
guard let date = calendar.date(from: components),
let range = calendar.range(of: .day, in: .month, for: date) else { return }
let days = Array(range)
I would like it in a date format where I can compare it to other date.
Once you have the year, month, and day, hour (converted to 24 hour value, from 0 to 23), you can build the Date object like so:
let calendar = Calendar.current
let components = DateComponents(year: year, month: month, day: day, hour: hour, minute: minute)
guard let date = calendar.date(from: components) else { return }
That date can now be compared to any other Date object.
So the purpose is to create a month view calendar with collection view. Today is the starting point, so I will get the first and last day of month in calendar from today.
func setDate(date: Date) {
let firstDate = date.start(of: .month)
let lastDate = date.end(of: .month)
}
Say today is 2017-07-19, instead of first date return 25th of June it return 30th of June and last date return 31st of July instead of 5th of August.
I could solve this by using the pure Swift Date Library, but I believe that this task could be solved by DateTools. I just don't know how.
By the way I'm using Swift 3.
DateTools Swift
I have a spreadsheet that asks people to enter in a day of the month when we need to send out a bill. What I want to do is create a calendar event based on that. So, essentially what I need is an event that starts at the current month, day from the spreadsheet, and continues to a specified point in time.
var monthlyDate = row[6]; // Seventh column, monthly date of payment
var curDate = new Date();
var curMonth = curDate.getMonth();
var curYear = curDate.getYear();
curDate.setDate(curMonth, monthlyDate, curYear);
Logger.log("Day of month: %s", monthlyDate);
Logger.log("Current Date: %s", curDate);
Logger.log("Current Date: %s", Date());
What I'm seeing is that the monthly date is coming in as a float "6.0" for example, and no matter what I enter in for monthlyDate in the setDate line, it keeps setting the date to 10/9/15 (Today is 10/15/15). I've hard-coded that value to many different numbers, but for some reason it's just not working.
How can I create a date (in any format) that follows the scheme "Current Month / Day from Speadsheet / Current Year" ?
The getMonth() method returns a "zero-indexed" number. So, it returns the number 9 for the 10th month. setDate() doesn't set the date, it sets the "Day of the Month". The name of that method is misleading.
Documentation - setDate()
So, the last two parameters that you are using in setDate() are doing nothing. You are setting the day of the month to 9.
If you want to set multiple date parameters at the same time, you need to use the new Date() method:
var d = new Date(year, month, day, hours, minutes, seconds, milliseconds);
The month parameter accept values from 0 to 11, 0 is Jan and 11 is Dec
Date Reference
I need to make my Access query always return the Monday of the current week. I have seen a few solutions on Google/StackOverflow but they are written in SQL and I am a beginner in creating Access queries (I am using the Design view to make them).
Goal: The week should be considered as M T W T F S S. Then, the query should always return the Monday of the current week. Therefore, if it is Sunday, it should still return the Monday before, NOT the next week's Monday. Can anyone explain how to do this using the Design View in Access 2010?
Keep in mind that in this context we are working with dates, so if we do Date() - 1, we will get 1 day prior to today.
Date() ~ Today's date
DatePart(
"w" - Weekday
Date() - Today's date
2 - vBMonday (Access assumes Sunday is the first day of the week, which is why this is necessary.)
1 - vbFirstJan1 - This gets into using the first week of the year. We could have omitted this, as 1 is the default.
)
-1 - Subtract 1 from the DatePart value.
Values
Date() = 4/27/2015 (at time of this writing)
DatePart("w",Date(),2,1) = 1
DatePart("w",Date(),2,1)-1 = 0
So we have Date()-0... Okay, what's so great about that? Well, let's look at a more useful scenario where today's date is a day other than Monday.
Let's act like today is 4/28/2015 (Tuesday)
Date() = 4/28/2015
DatePart("w",Date(),2,1) = 2
DatePart("w",Date(),2,1)-1 = 1
So, from the outside, in; give me the current weekday value. (1 = Monday, 2 = Tuesday, etc.), and subtract 1 from that -> that's how many days we need to subtract from the current date to get back to the weekday value of 1 (Monday).
Here's a function that will do this:
Public Function DatePrevWeekday( _
ByVal datDate As Date, _
Optional ByVal bytWeekday As VbDayOfWeek = vbMonday) _
As Date
' Returns the date of the previous weekday, as spelled in vbXxxxday, prior to datDate.
' 2000-09-06. Cactus Data ApS.
' No special error handling.
On Error Resume Next
DatePrevWeekday = DateAdd("d", 1 - Weekday(datDate, bytWeekday), datDate)
End Function
As vbMonday is 2 and your date is today, you can use the core expression in a query:
PreviousMonday: DateAdd("d",1-Weekday(Date(),2),Date())