diff --git a/src/ISO8601.cpp b/src/ISO8601.cpp
index ef7a62026..d6c0e73e7 100644
--- a/src/ISO8601.cpp
+++ b/src/ISO8601.cpp
@@ -141,6 +141,25 @@ ISO8601d::ISO8601d (const int m, const int d, const int y)
   _date = mktime (&t);
 }
 
+////////////////////////////////////////////////////////////////////////////////
+ISO8601d::ISO8601d (const int m,  const int d,  const int y,
+                    const int hr, const int mi, const int se)
+{
+  clear ();
+
+  // Error if not valid.
+  struct tm t = {0};
+  t.tm_isdst = -1;   // Requests that mktime determine summer time effect.
+  t.tm_mday  = d;
+  t.tm_mon   = m - 1;
+  t.tm_year  = y - 1900;
+  t.tm_hour  = hr;
+  t.tm_min   = mi;
+  t.tm_sec   = se;
+
+  _date = mktime (&t);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 ISO8601d::~ISO8601d ()
 {
diff --git a/src/ISO8601.h b/src/ISO8601.h
index a102534f1..559794f4e 100644
--- a/src/ISO8601.h
+++ b/src/ISO8601.h
@@ -40,6 +40,7 @@ public:
   ISO8601d ();
   ISO8601d (time_t);
   ISO8601d (const int, const int, const int);
+  ISO8601d (const int, const int, const int, const int, const int, const int);
   ~ISO8601d ();
   ISO8601d (const ISO8601d&);                 // Unimplemented
   ISO8601d& operator= (const ISO8601d&);      // Unimplemented