diff --git a/date.h b/date.h
index fd1e308..2793fbc 100644
--- a/date.h
+++ b/date.h
@@ -6673,7 +6673,7 @@ parse(const CharT* format, Parsable& tp,
 namespace detail
 {
 
-#if __cplusplus >= 201402
+#if __cplusplus >= 201402  && (!defined(__EDG_VERSION__) || __EDG_VERSION__ > 411)
 
 template <class CharT, std::size_t N>
 class string_literal
@@ -7055,7 +7055,7 @@ get_units(std::ratio<3600>)
     return string_literal<CharT, 2>{"h"};
 }
 
-#else  //  __cplusplus < 201402
+#else  // __cplusplus < 201402 || (defined(__EDG_VERSION__) && __EDG_VERSION__ <= 411)
 
 inline
 std::string
@@ -7271,7 +7271,7 @@ get_units(std::ratio<3600>)
     return {'h'};
 }
 
-#endif  //  __cplusplus >= 201402
+#endif  // __cplusplus < 201402 || (defined(__EDG_VERSION__) && __EDG_VERSION__ <= 411)
 
 template <class CharT, class Traits = std::char_traits<CharT>>
 struct make_string;