diff --git a/tz.h b/tz.h
index eec9ed9..5942838 100644
--- a/tz.h
+++ b/tz.h
@@ -1150,7 +1150,7 @@ tai_clock::utc_to_tai(utc_time<Duration> t)
     using namespace std::chrono;
     using duration = typename std::common_type<Duration, seconds>::type;
     return tai_time<duration>{t.time_since_epoch()} + 
-            (sys_days{1970_y/jan/1} - sys_days{1958_y/jan/1} + seconds{10});
+            (sys_days{year{1970}/jan/1} - sys_days{year{1958}/jan/1} + seconds{10});
 }
 
 template <class Duration>
@@ -1160,7 +1160,7 @@ tai_clock::tai_to_utc(tai_time<Duration> t)
     using namespace std::chrono;
     using duration = typename std::common_type<Duration, seconds>::type;
     return utc_time<duration>{t.time_since_epoch()} - 
-            (sys_days{1970_y/jan/1} - sys_days{1958_y/jan/1} + seconds{10});
+            (sys_days{year{1970}/jan/1} - sys_days{year{1958}/jan/1} + seconds{10});
 }
 
 template <class Duration>
@@ -1194,7 +1194,7 @@ operator<<(std::basic_ostream<CharT, Traits>& os, const tai_time<Duration>& t)
     using namespace std::chrono;
     using duration = typename std::common_type<Duration, seconds>::type;
     auto tp = sys_time<duration>{t.time_since_epoch()} -
-                (sys_days{1970_y/jan/1} - sys_days{1958_y/jan/1});
+                (sys_days{year{1970}/jan/1} - sys_days{year{1958}/jan/1});
     return os << tp;
 }
 
@@ -1235,7 +1235,7 @@ gps_clock::utc_to_gps(utc_time<Duration> t)
     using namespace std::chrono;
     using duration = typename std::common_type<Duration, seconds>::type;
     return gps_time<duration>{t.time_since_epoch()} -
-            (sys_days{1980_y/jan/sun[1]} - sys_days{1970_y/jan/1} + seconds{9});
+            (sys_days{year{1980}/jan/sun[1]} - sys_days{year{1970}/jan/1} + seconds{9});
 }
 
 template <class Duration>
@@ -1245,7 +1245,7 @@ gps_clock::gps_to_utc(gps_time<Duration> t)
     using namespace std::chrono;
     using duration = typename std::common_type<Duration, seconds>::type;
     return utc_time<duration>{t.time_since_epoch()} +
-            (sys_days{1980_y/jan/sun[1]} - sys_days{1970_y/jan/1} + seconds{9});
+            (sys_days{year{1980}/jan/sun[1]} - sys_days{year{1970}/jan/1} + seconds{9});
 }
 
 template <class Duration>
@@ -1279,7 +1279,7 @@ operator<<(std::basic_ostream<CharT, Traits>& os, const gps_time<Duration>& t)
     using namespace std::chrono;
     using duration = typename std::common_type<Duration, seconds>::type;
     auto tp = sys_time<duration>{t.time_since_epoch()} +
-                (sys_days{1980_y/jan/sun[1]} - sys_days{1970_y/jan/1});
+                (sys_days{year{1980}/jan/sun[1]} - sys_days{year{1970}/jan/1});
     return os << tp;
 }