Cocoa-Touch: How do I see if two NSDates are in the same day?

Question

I need to know if two NSDate instances are both from the same day.

Is there an easier/better way to do it than getting the NSDateComponents and comparing day/month/y

Answer 1

I create my own utility classes.

ZYUtility.h

@interface ZYUtility : NSObject
+ (NSDate *)yesterday;
+ (NSDate *)tomorrow;
+ (NSDate *)endOfDay:(NSDate *)date;
+ (NSDate *)beginningOfDay:(NSDate *)date;
@end

ZYUtility.m

+ (NSDate *)yesterday;
{
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *componets = [calendar components:NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit
                                              fromDate:[NSDate date]];
    componets.day -= 1;
    componets.hour = 24;
    componets.minute = 0;
    componets.second = 0;

    return [calendar dateFromComponents:componets];
}

+ (NSDate *)tomorrow;
{
    NSCalendar *calendar = [NSCalendar currentCalendar];
    NSDateComponents *componets = [calendar components:NSYearCalendarUnit | NSMonthCalendarUnit | NSDayCalendarUnit
                                              fromDate:[NSDate date]];
    componets.day += 1;
    componets.hour = 0;
    componets.minute = 0;
    componets.second = 0;

    return [calendar dateFromComponents:componets];
}

+ (NSDate *)beginningOfDay:(NSDate *)date {
    NSCalendar *calendar = [NSCalendar currentCalendar];

    unsigned unitFlags = NSYearCalendarUnit | NSMonthCalendarUnit |  NSDayCalendarUnit;
    NSDateComponents *comp = [calendar components:unitFlags fromDate:date];

    return [calendar dateFromComponents:comp];
}

+ (NSDate *)endOfDay:(NSDate *)date {
    NSCalendar *calendar = [NSCalendar currentCalendar];

    NSDateComponents *components = [NSDateComponents new];
    components.day = 1;

    NSDate *theDate = [calendar dateByAddingComponents:components
                                                toDate:[ZYUtility beginningOfDay:date]
                                               options:0];

    theDate = [theDate dateByAddingTimeInterval:-1];

    return theDate;
}