CODEWITHSUNDEEP
iosobjective-ccocoacocoa-touch
rustylepord
rustylepord

Reputation: 5801

Get previous working day

I need to get previous working date from the current date. For instance if the current day is monday , I need to get the date of Friday .

I have following code to get the previous date from the current date. 

-(NSDate*)previousDateFromDate:(NSDate*)date {

NSDate *now = date;
int daysToAdd = -1;

// set up date components
NSDateComponents *components = [[NSDateComponents alloc] init];
[components setDay:daysToAdd];

// create a calendar
NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:GregorianCalendar];
return [gregorian dateByAddingComponents:components toDate:now options:0];

}

How can I achieve this ? Is it by calculating difference of index of the current day ?

Upvotes: 0

Views: 256

Answers (2)

CRD
CRD

Reputation: 53000

You've got the right idea and using the weekday number is the way to go, comments in code:

-(NSDate*)previousDateFromDate:(NSDate*)date
{
   // Get the current calendar
   NSCalendar *currentCal = [NSCalendar currentCalendar];

   // Get current weekday, Sunday = 1
   NSDateComponents *comps = [currentCal components:NSWeekdayCalendarUnit fromDate:date];
   NSInteger weekday = comps.weekday;

   // Determine the number of days to go back, assuming Sat -> Mond should go to Fri
   NSInteger deltaDays = weekday == 1 ? -2 : (weekday == 2 ? -3 : -1);

   // Create componets with the offset
   NSDateComponents *offset = [NSDateComponents new];
   offset.day = deltaDays;

   // Calculate the required date
   return [currentCal dateByAddingComponents:offset toDate:date options:0];
}

This assumes the current calendar is the Gregorian one, you'll have to figure out if it works for others.

HTH

Upvotes: 1

Abhishek Sharma
Abhishek Sharma

Reputation: 3283

-(NSDate*)previousDateFromDate:(NSDate*)date {

    NSCalendar* cal = [NSCalendar currentCalendar];
    NSDateComponents* comp = [cal components:NSWeekdayCalendarUnit fromDate:date];

    //[comp weekday] =  1 = Sunday, 2 = Monday, etc.

    NSDate * returnDate;

    if([comp weekday] == 1){
        returnDate = [[NSDate date]dateByAddingTimeInterval:(-86400 * 2)];
    }else {
        returnDate = [[NSDate date]dateByAddingTimeInterval:-86400];
    }
    return returnDate;
}

Upvotes: 0

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