diff --git a/YYKit/Base/Foundation/NSDate+YYAdd.h b/YYKit/Base/Foundation/NSDate+YYAdd.h
index d9ecb11d..54317d2b 100644
--- a/YYKit/Base/Foundation/NSDate+YYAdd.h
+++ b/YYKit/Base/Foundation/NSDate+YYAdd.h
@@ -30,6 +30,7 @@ NS_ASSUME_NONNULL_BEGIN
 @property (nonatomic, readonly) NSInteger minute; ///< Minute component (0~59)
 @property (nonatomic, readonly) NSInteger second; ///< Second component (0~59)
 @property (nonatomic, readonly) NSInteger nanosecond; ///< Nanosecond component
+@property (nonatomic, readonly) NSInteger dayOfYear; ///< DayOfYear component (0~365/366)
 @property (nonatomic, readonly) NSInteger weekday; ///< Weekday component (1~7, first day is based on user setting)
 @property (nonatomic, readonly) NSInteger weekdayOrdinal; ///< WeekdayOrdinal component
 @property (nonatomic, readonly) NSInteger weekOfMonth; ///< WeekOfMonth component (1~5)
diff --git a/YYKit/Base/Foundation/NSDate+YYAdd.m b/YYKit/Base/Foundation/NSDate+YYAdd.m
index 3729088d..e071af35 100644
--- a/YYKit/Base/Foundation/NSDate+YYAdd.m
+++ b/YYKit/Base/Foundation/NSDate+YYAdd.m
@@ -46,6 +46,10 @@ - (NSInteger)nanosecond {
     return [[[NSCalendar currentCalendar] components:NSCalendarUnitSecond fromDate:self] nanosecond];
 }
 
+- (NSInteger)dayOfYear{
+    return [[NSCalendar currentCalendar] ordinalityOfUnit:NSCalendarUnitDay inUnit:NSCalendarUnitYear forDate:self];
+}
+
 - (NSInteger)weekday {
     return [[[NSCalendar currentCalendar] components:NSCalendarUnitWeekday fromDate:self] weekday];
 }