A sundial measures time only when the sun shines, so it is read as noticing the hours that count. Its moving shadow speaks of time passing and of attention to the present.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.