My Girl still does not fully comprehend the concept of time.
She often uses "yesterday" and "just now" to refer to a past event. The past event could be something that happened just yesterday or even last week.
However she appears to understand the future though ie she can differentiate between "afterwards" and "tomorrow" For example when I tell her "Its late. We'll play with this tomorrow." She'd say "No. No. I want to play afterwards."
Her kong kong (grandpa) says she's too smart. Hmmm... not sure if thats good or bad.