"The Mesenger of Allah was asked questions during the days of Mina and he said: 'There is no harm.' A man said: 'I shaved my head before offering the sacrifice.' He said: 'There is no harm.' Another man said: 'I stoned (the Majarat) after evening came.' He said: "There is no harm.'"
Sunan an-Nasa'i Book 24, Hadith 450