diff --git a/include/fc/time.hpp b/include/fc/time.hpp
index c5ae58a..4f2ce25 100644
--- a/include/fc/time.hpp
+++ b/include/fc/time.hpp
@@ -86,6 +86,10 @@ namespace fc {
         friend bool      operator == ( const time_point_sec& a, const time_point_sec& b ) { return a.utc_seconds == b.utc_seconds; }
         time_point_sec&  operator += ( uint32_t m ) { utc_seconds+=m; return *this; }
 
+        friend time_point   operator - ( const time_point_sec& t, const microseconds& m )   { return time_point(t) - m;             }
+        friend microseconds operator - ( const time_point_sec& t, const time_point_sec& m ) { return time_point(t) - time_point(m); }
+        friend microseconds operator - ( const time_point& t, const time_point_sec& m ) { return time_point(t) - time_point(m); }
+
     private:
         uint32_t utc_seconds;
   };