diff --git a/DateTools/DateTools/DTConstants.h b/DateTools/DateTools/DTConstants.h
index b9fcccf0..549cb6b8 100644
--- a/DateTools/DateTools/DTConstants.h
+++ b/DateTools/DateTools/DTConstants.h
@@ -23,6 +23,9 @@
 #import <Foundation/Foundation.h>
 
 FOUNDATION_EXPORT const long long SECONDS_IN_YEAR;
+FOUNDATION_EXPORT const long long SECONDS_IN_COMMON_YEAR;
+FOUNDATION_EXPORT const long long SECONDS_IN_JULIAN_YEAR;
+FOUNDATION_EXPORT const long long SECONDS_IN_LEAP_YEAR;
 FOUNDATION_EXPORT const NSInteger SECONDS_IN_MONTH_28;
 FOUNDATION_EXPORT const NSInteger SECONDS_IN_MONTH_29;
 FOUNDATION_EXPORT const NSInteger SECONDS_IN_MONTH_30;
diff --git a/DateTools/DateTools/DTConstants.m b/DateTools/DateTools/DTConstants.m
index 2320dea9..845bbfc0 100644
--- a/DateTools/DateTools/DTConstants.m
+++ b/DateTools/DateTools/DTConstants.m
@@ -21,7 +21,10 @@
 // CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 #import "DTConstants.h"
-const long long SECONDS_IN_YEAR = 31556900;
+const long long SECONDS_IN_YEAR = 31556952;
+const long long SECONDS_IN_COMMON_YEAR = 31536000;
+const long long SECONDS_IN_JULIAN_YEAR = 31557600;
+const long long SECONDS_IN_LEAP_YEAR = 31622400;
 const NSInteger SECONDS_IN_MONTH_28 = 2419200;
 const NSInteger SECONDS_IN_MONTH_29 = 2505600;
 const NSInteger SECONDS_IN_MONTH_30 = 2592000;