Calculate total number of weeks from two NSDate - ios

Question

I want to check if the current NSDate is 2 Weeks ahead of the another NSDate. I have can do somethings as below code but was wondering if there is any proper way to do.
[calendar rangeOfUnit:NSCalendarUnitDay startDate:&currentDate interval:NULL forDate:currentDate];
[calendar rangeOfUnit:NSCalendarUnitDay startDate:&previousDate interval:NULL forDate:previousDate];
NSDateComponents *difference = [calendar components:NSCalendarUnitDay fromDate:previousDate toDate:currentDate options:0];
if(diiference >= 14) {
}

Answer 1

You can use one trick here. First calculate number of days between 2 dates and then calculate number of weeks between them. You can do it like
-(NSInteger)weeksBetweenDate:(NSDate*)fromDateTime andDate:(NSDate*)toDateTime {
NSDate *fromDate;
NSDate *toDate;
NSCalendar *calendar = [NSCalendar currentCalendar];
[calendar rangeOfUnit:NSCalendarUnitDay startDate:&fromDate
interval:NULL forDate:fromDateTime];
[calendar rangeOfUnit:NSCalendarUnitDay startDate:&toDate
interval:NULL forDate:toDateTime];
NSDateComponents *difference = [calendar components:NSCalendarUnitDay
fromDate:fromDate toDate:toDate options:0];
return [difference day] / 7;
}
You can use CGFloat if you want to get week value like 1.5 and keep as it is if you want week count like 1,2,3,etc

Answer 2

Try this
objective C
+ (NSInteger)daysBetweenDate:(NSDate*)fromDateTime andDate:(NSDate*)toDateTime
{
NSDate *fromDate;
NSDate *toDate;
NSCalendar *calendar = [NSCalendar currentCalendar];
[calendar rangeOfUnit:NSCalendarUnitDay startDate:&fromDate
interval:NULL forDate:fromDateTime];
[calendar rangeOfUnit:NSCalendarUnitDay startDate:&toDate
interval:NULL forDate:toDateTime];
NSDateComponents *difference = [calendar components:NSCalendarUnitDay
fromDate:fromDate toDate:toDate options:0];
return [difference day];
}
Swift
extension NSDate {
func numberOfDaysUntilDateTime(toDateTime: NSDate, inTimeZone timeZone: NSTimeZone? = nil) -> Int {
let calendar = NSCalendar.currentCalendar()
if let timeZone = timeZone {
calendar.timeZone = timeZone
}
var fromDate: NSDate?, toDate: NSDate?
calendar.rangeOfUnit(.Day, startDate: &fromDate, interval: nil, forDate: self)
calendar.rangeOfUnit(.Day, startDate: &toDate, interval: nil, forDate: toDateTime)
let difference = calendar.components(.Day, fromDate: fromDate!, toDate: toDate!, options: [])
return difference.day
}
}