iPhone NSDate eg. next Friday - objective-c

Question

I want to create a function which results the date of next Friday but I have no plan how to do it. Has anyone a good hint to me ?

Answer 1

E.g. Get current date using NSDate, then use 'components>fromDate:' from NSCalendar to get the NSDateComponents, then add the time difference to next Friday and create a new NSDate and Bob's is your uncle.

Answer 2

Here is my working solution for getting the next 5 Sundays in Gregorian calendar:
self.nextBeginDates = [NSMutableArray array];
NSDateComponents *weekdayComponents = [[NSCalendar currentCalendar] components:NSWeekdayCalendarUnit fromDate:[NSDate date]];
int currentWeekday = [weekdayComponents weekday]; //[1;7] ... 1 is sunday, 7 is saturday in gregorian calendar
NSDateComponents *comp = [[NSDateComponents alloc] init];
[comp setDay:8 - currentWeekday]; // add some days so it will become sunday
// build weeks array
int weeksCount = 5;
for (int i = 0; i < weeksCount; i++) {
[comp setWeek:i]; // add weeks
[nextBeginDates addObject:[[NSCalendar currentCalendar] dateByAddingComponents:comp toDate:[NSDate date] options:0]];
}
[comp release];

Answer 3

This should work
+ (NSDate *) dateForNextWeekday: (NSInteger)weekday {
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];
/*
Add components to get to the weekday we want
*/
NSDateComponents *componentsToSubtract = [[NSDateComponents alloc] init];
NSInteger dif = weekday-weekdayComponents.weekday;
if (dif<=0) dif += 7;
[componentsToSubtract setDay:dif];
NSDate *beginningOfWeek = [gregorian dateByAddingComponents:componentsToSubtract
toDate:today options:0];
return beginningOfWeek;
}

Answer 4

Keep it simple, safe, and readable! (....KISSAR?)
#define FRIDAY 6
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *dayComponent = [[NSDateComponents alloc] init];
dayComponent.day = 1;
NSDate *nextFriday = [NSDate date];
NSInteger iWeekday = [[gregorian components:NSWeekdayCalendarUnit fromDate:nextFriday] weekday];
while (iWeekday != FRIDAY) {
nextFriday = [gregorian dateByAddingComponents:dayComponent toDate:nextFriday options:0];
iWeekday = [[gregorian components:NSWeekdayCalendarUnit fromDate:nextFriday] weekday];
}
Now nextFriday has your date.
Hope this helps!
EDIT
Note that if the current date was already a Friday, it would return that instead of the next Friday. If that's undesirable just init your nextFriday to a day later (so if current date was a Friday, it would start on Saturday, forcing the next Friday. And if current date was a Thursday you'd automatically have your next Friday without needing the loop).

Answer 5

Here is my solution, and just to warn you, on a saturday is the friday before shown.
cheers to all
NSDate *today = [[NSDate alloc] init];
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar];
NSDateComponents *weekdayComponents = [gregorian components:NSWeekdayCalendarUnit fromDate:today];
int weekday = [weekdayComponents weekday];
int iOffsetToFryday = -weekday + 6;
weekdayComponents.weekday = iOffsetToFryday;
NSDate *nextFriday = [[NSCalendar currentCalendar] dateByAddingComponents:weekdayComponents toDate:today options:0];