In what year did the Isra and Mi'raj occur?

Scholars have differed on the timing of the Isra and Mi'raj incident. Some said it was one year before the Hijra, and Ibn Hazm claimed a consensus on this, while Al-Qadi said it was five years before the Hijra. They also differed on which month it occurred. Ibn al-Athir and Al-Nawawi definitively stated that it was on the night of the twenty-seventh of Rabi' al-Awwal. It was also said to have been in Rajab, or in Ramadan, or in Shawwal.