It seems quite simple to allocate 10 - 15 minutes in the morning for a piano. At least much easier than to find later time for a longer session during the day.

There is a similar (and very good) ["ten minute" question](https://music.stackexchange.com/questions/1585/ten-minute-practice-techniques) for guitar but most of answers there are instrument specific. Would it be possible to get recommendations on how to use short but daily time for a piano the most efficiently? Especially, does it make more sense to learn new thing or just play the known pieces?