diff --git a/src/lib/time.c b/src/lib/time.c
index 5af40d640..3748d7e8d 100644
--- a/src/lib/time.c
+++ b/src/lib/time.c
@@ -91,3 +91,16 @@ lumiera_time_millis(gavl_time_t time)
 {
   return (time / GAVL_TIME_SCALE_MS) % 1000;
 }
+
+int
+lumiera_time_frames(gavl_time_t time, float fps)
+{
+  return (fps * (lumiera_time_millis(time))) / 1000;
+}
+
+int
+lumiera_time_frame_count(gavl_time_t time, float fps)
+{
+  int ms = (time / GAVL_TIME_SCALE_MS);
+  return fps * ms / 1000;
+}
diff --git a/src/lib/time.h b/src/lib/time.h
index f812c1b9d..4a3812238 100644
--- a/src/lib/time.h
+++ b/src/lib/time.h
@@ -60,5 +60,19 @@ int lumiera_time_seconds(gavl_time_t time);
  */
 int lumiera_time_millis(gavl_time_t time);
 
+/**
+ * Get the frame part of given time, using the given number of frames.
+ * @param gavl_time_t the time we are interested in converting
+ * @param fps Frame rate (float for now, but should be a rational)
+ */
+int lumiera_time_frames(gavl_time_t time, float fps);
+
+/**
+ * Get the frame count for the given time.
+ * @param gavl_time_t the time we are interested in converting
+ * @param fps Frame rate (float for now, but should be a rational)
+ */
+int lumiera_time_frame_count(gavl_time_t time, float fps);
+
 #endif
 
diff --git a/tests/library/test-time.c b/tests/library/test-time.c
index 4ce8b63bb..fc0f4f343 100644
--- a/tests/library/test-time.c
+++ b/tests/library/test-time.c
@@ -32,6 +32,7 @@ const int MILLIS = 700;
 const int SECONDS = 20;
 const int MINUTES = 55;
 const int HOURS = 3;
+const float FPS = 24.0;
 
 /*
  * 1. Basic functionality
@@ -46,6 +47,10 @@ TEST (basic) {
   CHECK (lumiera_time_seconds(t)            == 0);
   CHECK (lumiera_time_minutes(t)            == 0);
   CHECK (lumiera_time_hours(t)              == 0);
+  CHECK (lumiera_time_frames(t, FPS)        == 0);
+  CHECK (lumiera_time_frames(t, FPS+5)      == 0);
+  CHECK (lumiera_time_frame_count(t, FPS)   == 0);
+  CHECK (lumiera_time_frame_count(t, FPS+5) == 0);
 
   ECHO ("%s", lumiera_tmpbuf_print_time(t));
 
@@ -56,6 +61,10 @@ TEST (basic) {
   CHECK (lumiera_time_seconds(t)            == SECONDS);
   CHECK (lumiera_time_minutes(t)            == MINUTES);
   CHECK (lumiera_time_hours(t)              == HOURS);
+  CHECK (lumiera_time_frames(t, FPS)        == (int)((FPS * MILLIS) / 1000));
+  CHECK (lumiera_time_frames(t, FPS+5)      == (int)(((FPS+5) * MILLIS) / 1000));
+  CHECK (lumiera_time_frame_count(t, FPS)   == 338896);
+  CHECK (lumiera_time_frame_count(t, FPS+5) == 409500);
 
   ECHO ("%s", lumiera_tmpbuf_print_time(t));
 }