NSCalendar和NSDate

#import 

@interface NSCalendar (CqExtension)

+ (instancetype)Cq_calendar;

@end

---------------------------------------------------



#import "NSCalendar+CqExtension.h"

@implementation NSCalendar (CqExtension)

+ (instancetype)Cq_calendar{
    // 判断NSCalendar这个类是否有calendarWithIdentifier:这个[类方法],类方法判断是否存在方法可以用于版本的判断
    if ([NSCalendar respondsToSelector:@selector(calendarWithIdentifier:)]) {
        return [NSCalendar calendarWithIdentifier:NSCalendarIdentifierGregorian];
    }else{
        return [NSCalendar currentCalendar];
    }
}

#import 

@interface CqDateItem : NSObject

/** 天 */
@property (nonatomic,assign) NSInteger day;
/** 时 */
@property (nonatomic,assign) NSInteger hour;
/** 分 */
@property (nonatomic,assign) NSInteger minute;
/** 秒 */
@property (nonatomic,assign) NSInteger second;

@end

@interface NSDate (CqExtension)

- (CqDateItem *)Cq_timeIntervalSinceDate:(NSDate *)anotherDate;

//是否当前天
- (BOOL)Cq_isToday;
//是否昨天
- (BOOL)Cq_isYesterday;
//是否当前天
- (BOOL)Cq_isTomorrow;
//是否今年
- (BOOL)Cq_isThisYear;

@end
---------------------------------------------------
#import "NSDate+CqExtension.h"
#import "NSCalendar+CqExtension.h"

@implementation CqDateItem

- (NSString *)description{
    return [NSString stringWithFormat:@"%zd天%zd时%zd分%zd秒",self.day,self.hour,self.minute,self.second];
    
}

@end

@implementation NSDate (CqExtension)

- (CqDateItem *)Cq_timeIntervalSinceDate:(NSDate *)anotherDate{
    
    //创建时间createAtDate 和 nowDate的时间间隔
    NSTimeInterval interval = [self timeIntervalSinceDate:anotherDate];
    
    CqDateItem *item = [[CqDateItem alloc] init];
    
    //相差多少天
    int intInterval = (int)interval;
    int secondPerDay = 24 * 3600;
    item.day = intInterval / secondPerDay;
    
    //相差几小时
    int secondPerHour = 3600;
    item.hour = (intInterval % secondPerDay) / secondPerHour;
    
    //相差几分钟
    int secondPerMinute = 60;
    item.minute = ((intInterval % secondPerDay) % secondPerHour) / secondPerMinute;
    
    //相差几秒
    item.second = ((intInterval % secondPerDay) % secondPerHour) % secondPerMinute;
    
    return item;
    
    
}

- (BOOL)Cq_isToday{
    //判断self这日期是否是今天
    NSCalendar *calendar = [NSCalendar Cq_calendar];
    
    NSCalendarUnit unit = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay;
    
    NSDateComponents *selfCmp = [calendar components:unit fromDate:self];
    NSDateComponents *nowCmp = [calendar components:unit fromDate:[NSDate date]];
    
   return  [selfCmp isEqual:nowCmp];
    
    
}

- (BOOL)Cq_isYesterday{
    
    // self 2015-12-09 22:10:01 -> 2015-12-09 00:00:00
    // now  2015-12-10 12:10:01 -> 2015-12-01 00:00:00
    // 昨天：0year 0month 1day 0hour 0minute 0second
    
    
    // NSDate * -> NSString * -> NSDate *
    
    
    //判断这日期是否昨天
    NSDateFormatter *fmt = [[NSDateFormatter alloc] init];
    fmt.dateFormat = @"yyyyMMdd";
    
    //生成只有年月日的字符串对象
    NSString *selfString = [fmt stringFromDate:self];
    NSString *nowString = [fmt stringFromDate:[NSDate date]];
    
    //生成只有年月日的日期对象
    NSDate *selfDate = [fmt dateFromString:selfString];
    NSDate *nowDate = [fmt dateFromString:nowString];
    
    NSCalendar *calendar = [NSCalendar Cq_calendar];
    NSCalendarUnit unit = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay;
    NSDateComponents *cmps = [calendar components:unit fromDate:selfDate toDate:nowDate options:0];
    
    return cmps.year == 0
    && cmps.month == 0
    && cmps.day == 1;
    
    
    
}

- (BOOL)Cq_isTomorrow{
    //判断这日期是否昨天
    NSDateFormatter *fmt = [[NSDateFormatter alloc] init];
    fmt.dateFormat = @"yyyyMMdd";
    
    //生成只有年月日的字符串对象
    NSString *selfString = [fmt stringFromDate:self];
    NSString *nowString = [fmt stringFromDate:[NSDate date]];
    
    //生成只有年月日的日期对象
    NSDate *selfDate = [fmt dateFromString:selfString];
    NSDate *nowDate = [fmt dateFromString:nowString];
    
    NSCalendar *calendar = [NSCalendar Cq_calendar];
    NSCalendarUnit unit = NSCalendarUnitYear | NSCalendarUnitMonth | NSCalendarUnitDay;
    NSDateComponents *cmps = [calendar components:unit fromDate:selfDate toDate:nowDate options:0];
    
    return cmps.year == 0
    && cmps.month == 0
    && cmps.day == -1;
}

- (BOOL)Cq_isThisYear{
    
    //判断self的日期是否今年
    NSCalendar *calendar = [NSCalendar Cq_calendar];
    
    NSInteger selfYear = [calendar components:NSCalendarUnitYear fromDate:self].year;
    
    NSInteger nowYear = [calendar components:NSCalendarUnitYear fromDate:[NSDate date]].year;
    
    
    return selfYear == nowYear;
}