NSDate *now = [NSDate date];
NSDate *yesterday = [now dateByAddingTimeInterval:-86400];
NSDate *tomorrow = [now dateByAddingTimeInterval:86400];

NSCalendar *calendar = [NSCalendar currentCalendar];
NSDateComponents *component = [NSDateComponents new];
component.month = 1;
NSDate *nextMonth = [
                     calendar dateByAddingComponents:component toDate:now options:0];

component = [NSDateComponents new];
component.year = 1;
NSDate *nextYear = [
                    calendar dateByAddingComponents:component toDate:now options:0];