diff --git a/apps/polymath/README.md b/apps/polymath/README.md
index d9102bb05..bbe198452 100644
--- a/apps/polymath/README.md
+++ b/apps/polymath/README.md
@@ -4,3 +4,11 @@ The clock does not show widgets but a custom battery indicator.
 You can revert this in the code easily by uncommenting the respective lines.
 
 ![Image](polymathclock.jpg "photo")
+
+The top line shows battery status.
+The line below indicates noon and midnight on 24h timeline.
+ToDo: show daylight sunshine duration according to geolocation.
+Number in the middle is hour and minutes, in 12h format.
+Bottom row: days in the week, with current date, and moonphase
+placed on the date of next change of moon quartal (full moon, half moon etc)
+