NSDate - Getting Days of the Month (Not Days of the year)? - iphone

Using NSDateComponents I know how to get the day component, but this gives me a value from 1 - 365, right? I need to get the days 1-30 of a specific month, how can I?
For example, I have an NSDate which might be 16th May. I want to be able to get the day, so it returns 16. Being the 16th day of that month (not the 16th day of the year).
Thanks.
EDIT:
I have this:
NSCalendar *cal = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *comps = [cal components:NSDayCalendarUnit fromDate:[[NSUserDefaults standardUserDefaults] objectForKey:#"dateSaved"]];
However comps.day returns 1 when it should equal what the date is saved as, say 4.

The day value of NSDateComponents gives you the day of month according to the given calendar:
NSDate *date = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *comps = [gregorian components:NSDayCalendarUnit fromDate:date];
NSLog(#"%# / %d", date, comps.day);
gives
2012-02-04 15:27:36.682 testapp[1533:f803] 2012-02-04 14:27:36 +0000 / 4
although February, 4th would be the 35th day of the year.

Related

How to get start date and end date of a week in ios [duplicate]

This question already has answers here:
Current Week Start and End Date
(18 answers)
Closed 6 years ago.
please have a look to following lines of code:
NSCalendar *calendar = [NSCalendar currentCalendar];
NSInteger weekNumber = [[calendar components: NSWeekCalendarUnit fromDate:date] week];
now how we can get the first and last day of the given week number (assume that the week starts from monday to sunday).
also if it possible to get the array of all the dates belongs to the same week number.
To get the first day of the week the following code can be used.
NSDate *now = [NSDate date];
NSCalendar *calendar = [NSCalendar currentCalendar];
NSInteger weekNumber = [[calendar components: NSWeekCalendarUnit fromDate:now] week];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *comp = [gregorian components:NSYearCalendarUnit fromDate:now];
[comp setWeek:weekNumber]; //Week number.
[comp setWeekday:1]; //First day of the week. Change it to 7 to get the last date of the week
NSDate *resultDate = [gregorian dateFromComponents:comp];
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:#"MMM d, yyyy"];
NSString *myDateString = [formatter stringFromDate:resultDate];
NSLog(#"%#",myDateString);
as commented in the above code change the parameter of setWeekday method to 7 to get the last day of the week.
Once u have the first day and last day of the week u can get all the dates as mentioned in the below link.
Array for dates between two dates
Note: The week starts from Monday for the region setting UK.
To change the iPhone Calendar to show Monday as the first day of the week.
1. tap "Settings"
2. tap "General"
3. tap "International"
4. tap "Region Format"
5. select "united kingdom"

Calculate Year From current NSDate

I want to calculate the year from current NSDate. Suppose my current date 14-06-2012 so, what would be last date after end of year. (In simple way I can explain you that, if I have date 01-01-2012 then after end of year I would get 31-12-2012). So, how do I calculate year form current date.
Following output I expect for my project:
Next or End year Date where year end (Like 31-12-2012).
Next or end year month (Last date month).
Next or end year (Last date year or next year).
It Should be NSDate format. Hope you would able to understand my point.
NSDate *today = [NSDate date];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *comps = [gregorian components:(NSYearCalendarUnit) fromDate:today];
[comps setDay:31]; // last day of year is always the same
[comps setMonth:12];
NSInteger year = [comps year]; // the current year
NSDate *lastDayOfYear = [gregorian dateFromComponents:comps]; // the last day of the year
You can use this:
NSDate *now = [NSDate date];
NSDateComponents *dc = [[NSDateComponents alloc] init];
[dc setYear:1];
NSDate *targetDateObject = [[NSCalendar currentCalendar] dateByAddingComponents:dc toDate:now options:0];
[dc release];

Get first and last day of week for a couple of weeks

I need to make a calendar in which the user can scroll between several weeks. The first and last day of the week will be displayed like (e.g.) "June 4 - June 10".
Now I knew from the beginning that I'd need NSDate and NSCalendar, and indeed I managed to get the first and last day of just thist week, but it looks extremely cumbersome and I am sure there needs to be an easier method, as I need to get the dates for several more coming and past weeks.
This is my code which gives the day and month of the first and last day of the current week:
NSDate *today = [NSDate date];
NSCalendar* cal = [NSCalendar currentCalendar];
NSDateComponents* comp = [cal components:(NSWeekdayCalendarUnit|NSMonthCalendarUnit|NSWeekCalendarUnit|NSYearCalendarUnit|NSDayCalendarUnit|NSHourCalendarUnit) fromDate:[NSDate date]];
NSDate *beginOfWeek = [today dateByAddingTimeInterval: -1*([comp weekday]-2)*24*3600];
NSDate *endOfWeek = [today dateByAddingTimeInterval:(7-[comp weekday]+2)*24*3600];
NSLog(#"beginWeekDay=%d\n",[[cal components:(NSWeekdayCalendarUnit|NSMonthCalendarUnit|NSWeekCalendarUnit|NSDayCalendarUnit) fromDate: beginOfWeek] day]);
NSLog(#"endWeekDay=%d\n",[[cal components:(NSWeekdayCalendarUnit|NSMonthCalendarUnit|NSWeekCalendarUnit|NSDayCalendarUnit) fromDate: endOfWeek] day]);
NSLog(#"beginWeekmonth=%d\n",[[cal components:(NSWeekdayCalendarUnit|NSMonthCalendarUnit|NSWeekCalendarUnit|NSDayCalendarUnit) fromDate: beginOfWeek] month]);
NSLog(#"endWeekmonth=%d\n",[[cal components:(NSWeekdayCalendarUnit|NSMonthCalendarUnit|NSWeekCalendarUnit|NSDayCalendarUnit) fromDate: endOfWeek] month]);
I found this, which may be helpful to you: http://www.cocoanetics.com/2009/11/add-one-week-skip-weekend/
- (NSDate *)addWeekToDateAndSkipWeekend:(NSDate *)now {
int daysToAdd = 6; // we'll add the 7th later
// set up date components
NSDateComponents *components = [[[NSDateComponents alloc] init] autorelease];
[components setDay:daysToAdd];
// create a calendar
NSCalendar *gregorian = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];
NSDate *newDate = [gregorian dateByAddingComponents:components toDate:now options:0];
[components setDay:1]; // reuse to skip single days
NSDateComponents *newDateComps; // new componets to get weekday
// do always executed once, so we add the 7th day here
do
{
// add one day
newDate = [gregorian dateByAddingComponents:components toDate:newDate options:0];
newDateComps = [gregorian components:NSWeekdayCalendarUnit fromDate:newDate];
// repeat if the date is Saturday (7) or Sunday (1)
NSLog(#"weekday: %d", [newDateComps weekday]);
} while (([newDateComps weekday]==7)||([newDateComps weekday]==1));
return newDate;
}
Theoretically, you run this in a for loop with [NSDate date] and you will get the 7th day returned, you would then run the returned 7th day through this and get the next..etc..
May need minor alteration, to remove the check for Saturday+Sunday if you don't need it.
Hope this helps !

iPhone SDK, how to get NSDate object of coming friday's 20:00?

Does anyone know how to get the NSDate of the coming friday's 20:00 ?
Yes, this article teaches you how to get the current week's Sunday.
I quickly adapted it to get friday at 20:00 (Assuming a Gregorian calendar)
NSDate *today = [[NSDate alloc] init];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
// Get the weekday component of the current date
NSDateComponents *weekdayComponents = [gregorian components:NSWeekdayCalendarUnit fromDate:today];
/*
Create a date components to represent the number of days to add to the current date.
The weekday value for Friday in the Gregorian calendar is 6, so add the difference between 6 and today to get the number of days to add.
Actually, on Saturday that will give you -1, so you want to subtract from 13 then take modulo 7
*/
NSDateComponents *componentsToAdd = [[NSDateComponents alloc] init];
[componentsToAdd setDay: (13 - [weekdayComponents weekday]) % 7];
NSDate *friday = [gregorian dateByAddingComponents:componentsToAdd toDate:today options:0];
/*
friday now has the same hour, minute, and second as the original date (today).
To normalize to midnight, extract the year, month, and day components and create a new date from those components.
*/
NSDateComponents *components =
[gregorian components:(NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit)
fromDate: friday];
// And to set the time to 20:00
[components setHour:22];
friday = [gregorian dateFromComponents:components];

NSCalendar first day of week

Does anyone know if there is a way to set the first day of the week on a NSCalendar, or is there a calendar that already has Monday as the first day of the week, instead of Sunday.
I'm currently working on an app that is based around a week's worth of work, and it needs to start on Monday, not Sunday. I can most likely do some work to work around this, but there will be a lot of corner cases. I'd prefer the platform do it for me.
Thanks in advance
Here's some the code that I'm using. it's saturday now, so what I would hope is that weekday would be 6, instead of 7. that would mean that Sunday would be 7 instead of rolling over to 0
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
[gregorian setFirstWeekday:0];
unsigned unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit | NSWeekCalendarUnit | NSWeekdayCalendarUnit;
NSDateComponents *todaysDate = [gregorian components:unitFlags fromDate:[NSDate date]];
int dayOfWeek = todaysDate.weekday;
Edit: This does not check the edge case where the beginning of the week starts in the prior month. Some updated code to cover this: https://stackoverflow.com/a/14688780/308315
In case anyone is still paying attention to this, you need to use
ordinalityOfUnit:inUnit:forDate:
and set firstWeekday to 2. (1 == Sunday and 7 == Saturday)
Here's the code:
NSCalendar *gregorian = [[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar] autorelease];
[gregorian setFirstWeekday:2]; // Sunday == 1, Saturday == 7
NSUInteger adjustedWeekdayOrdinal = [gregorian ordinalityOfUnit:NSWeekdayCalendarUnit inUnit:NSWeekCalendarUnit forDate:[NSDate date]];
NSLog(#"Adjusted weekday ordinal: %d", adjustedWeekdayOrdinal);
Remember, the ordinals for weekdays start at 1 for the first day of the week, not zero.
Documentation link.
This code constructs a date that is set to Monday of the current week:
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *today = [NSDate date];
NSDate *beginningOfWeek = nil;
BOOL ok = [gregorian rangeOfUnit:NSWeekCalendarUnit startDate:&beginningOfWeek
interval:NULL forDate: today];
setFirstWeekday: on the NSCalendar object.
Sets the index of the first weekday for the receiver.
- (void)setFirstWeekday:(NSUInteger)weekday
Should do the trick.
In my opinion this settings should be dynamic according to the user locale.
Therefore one should use:
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
[gregorian setLocale:[NSLocale currentLocale]];
This will cause the calendar to set the first week day according to the user locale automatically. Unless you are developing your app for a specific purpose/user locale (or prefer to allow the user to choose this day).
I've done it like this.
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDate *today = [NSDate date];
NSDateComponents *compForWeekday = [gregorian components:(NSWeekdayCalendarUnit) fromDate:today];
NSInteger weekDayAsNumber = [compForWeekday weekday]; // The week day as number but with sunday starting as 1
weekDayAsNumber = ((weekDayAsNumber + 5) % 7) + 1; // Transforming so that monday = 1 and sunday = 7
I had trouble with a lot of the answers here. . maybe it was just me. .
Here's an answer that works for me:
- (NSDate*)firstDayOfWeek
{
NSCalendar* cal = [[NSCalendar currentCalendar] copy];
[cal setFirstWeekday:2]; //Override locale to make week start on Monday
NSDate* startOfTheWeek;
NSTimeInterval interval;
[cal rangeOfUnit:NSWeekCalendarUnit startDate:&startOfTheWeek interval:&interval forDate:self];
return startOfTheWeek;
}
- (NSDate*)lastDayOfWeek
{
NSCalendar* cal = [[NSCalendar currentCalendar] copy];
[cal setFirstWeekday:2]; //Override locale to make week start on Monday
NSDate* startOfTheWeek;
NSTimeInterval interval;
[cal rangeOfUnit:NSWeekCalendarUnit startDate:&startOfTheWeek interval:&interval forDate:self];
return [startOfTheWeek dateByAddingTimeInterval:interval - 1];
}
Update:
As pointed out (elsewhere) by #vikingosegundo, in general its best to let the local determine which day is the start of the week, however in this case the OP was asking for the start of the week to occur on Monday, hence we copy the system calendar, and override the firstWeekDay.
The problem with Kris' answer is the edge case where the beginning of the week starts in the prior month. Here's some easier code and it also checks the edge case:
// Finds the date for the first day of the week
- (NSDate *)getFirstDayOfTheWeekFromDate:(NSDate *)givenDate
{
NSCalendar *calendar = [NSCalendar currentCalendar];
// Edge case where beginning of week starts in the prior month
NSDateComponents *edgeCase = [[NSDateComponents alloc] init];
[edgeCase setMonth:2];
[edgeCase setDay:1];
[edgeCase setYear:2013];
NSDate *edgeCaseDate = [calendar dateFromComponents:edgeCase];
NSDateComponents *components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSWeekCalendarUnit|NSWeekdayCalendarUnit fromDate:edgeCaseDate];
[components setWeekday:1]; // 1 == Sunday, 7 == Saturday
[components setWeek:[components week]];
NSLog(#"Edge case date is %# and beginning of that week is %#", edgeCaseDate , [calendar dateFromComponents:components]);
// Find Sunday for the given date
components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSWeekCalendarUnit|NSWeekdayCalendarUnit fromDate:givenDate];
[components setWeekday:1]; // 1 == Sunday, 7 == Saturday
[components setWeek:[components week]];
NSLog(#"Original date is %# and beginning of week is %#", givenDate , [calendar dateFromComponents:components]);
return [calendar dateFromComponents:components];
}
I see misunderstanding in the other messages. The first weekday, whichever it is, has number 1 not 0. By default Sunday=1 as in the "Introduction to Date and Time Programming Guide for Cocoa: Calendrical Calculations":
"The weekday value for Sunday in the Gregorian calendar is 1"
For the Monday as a first workday the only remedy I have is brute force condition to fix the calculation
NSCalendar *cal=[[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *comps = [cal components:NSWeekdayCalendarUnit fromDate:[NSDate date]];
// set to 7 if it's Sunday otherwise decrease weekday number
NSInteger weekday=[comps weekday]==1?7:[comps weekday]-1;
Below also covers the edge case,
- (NSDate *)getFirstDayOfTheWeekFromDate:(NSDate *)givenDate
{
NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *components = [calendar components:NSYearCalendarUnit|NSMonthCalendarUnit|NSWeekCalendarUnit|NSWeekdayCalendarUnit fromDate:givenDate];
[components setWeekday:2]; // 1 == Sunday, 7 == Saturday
if([[calendar dateFromComponents:components] compare: curDate] == NSOrderedDescending) // if start is later in time than end
{
[components setWeek:[components week]-1];
}
return [calendar dateFromComponents:components];
}
You can just change .firstWeekday of the calendar.
NSCalendar *calendar = [[NSCalendar alloc] initWithCalendarIdentifier:NSCalendarIdentifierGregorian];
calendar.firstWeekday = 2;
Then use rangeOfUnit:startDate:interval:forDate: to get the first day
NSDate *startOfWeek;
[calendar rangeOfUnit:NSCalendarUnitWeekOfYear startDate:&startOfWeek interval:nil forDate:[NSdate date]];
Try this:
NSCalendar *yourCal = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]
[yourCal setFirstWeekday:0];
Iv found out the way to display any weekday name using nscalender..using the following code..
Just open your console from xcode menu bar to see the results.Copy Paste the following code in your viewDidLoad method to get the first day of the week
NSDate *today = [NSDate date];
NSDateFormatter *dateFormat = [[NSDateFormatter alloc] init];
[dateFormat setDateFormat:#"MM/dd/yyyy :EEEE"];
NSString *dateString = [dateFormat stringFromDate:today];
NSLog(#"date: %#", dateString);
[dateFormat release];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *components = [gregorian components:NSWeekdayCalendarUnit | NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit fromDate:today];
[components setDay:([components day]-([components weekday]-1))];
NSDate *beginningOfWeek = [gregorian dateFromComponents:components];
NSDateFormatter *dateFormat_first = [[NSDateFormatter alloc] init];
[dateFormat_first setDateFormat:#"MM/dd/yyyy :EEEE"];
NSString *dateString_first = [dateFormat_first stringFromDate:beginningOfWeek];
NSLog(#"First_date: %#", dateString_first);
The Output will be:
date: 02/11/2010 :Thursday
First_date: 02/07/2010 :Sunday
since i had run this program on 2/11/2010 u will get the desired output depending on the current date.
Similarly if u want to get the first working day of the week i.e Monday's date then just modify the code a bit:
CHANGE :[components setDay:([components day]-([components weekday]-1))];
TO
[components setDay:([components day]-([components weekday]-2))];
to get Mondays date for that week..
Similarly u can try to find the date of any of seven workdays by changing the integer -1,-2 and so on...
Hope u r question is answered..
Thanks,
Bonson Dias
The ISO 8601 calendar appears to have it's first weekday set to monday by default.
Using the Calendar nextWeekend (iOS 10 or later) and ordinality (thanks #kris-markel). I've gotten Monday as first of the week for the en_US calendar.
Here is an example of it with fallback to firstWeekday:
extension Calendar {
var firstWorkWeekday: Int {
guard #available(iOS 10.0, *) else{
return self.firstWeekday
}
guard let endOfWeekend = self.nextWeekend(startingAfter: Date())?.end else {
return self.firstWeekday
}
return self.ordinality(of: .weekday, in: .weekOfYear, for: endOfWeekend) ?? self.firstWeekday
}
}
The Swift solution (note, use .yearForWeekOfYear, not .year):
let now = Date()
let cal = Calendar.current
var weekComponents = cal.dateComponents([.yearForWeekOfYear, .weekOfYear,
.weekday], from: now)
//weekComponents.weekday = 1 // if your week starts on Sunday
weekComponents.weekday = 2 // if your week starts on Monday
cal.date(from: weekComponents) // returns date with first day of the week
… is there a calendar that already has Monday as the first day of the week, instead of Sunday.
Someday, there will be.
My simple way of doing this is to get Monday = 0, Sunday = 6:
NSDateComponents *dateComponents = [[NSCalendar currentCalendar] components:NSWeekdayCalendarUnit fromDate:[NSDate date]];
NSInteger dayNumStartingFromMonday = ([dateComponents weekday] - 2 + 7) % 7; //normal: Sunday is 1, Monday is 2