When did the Battle of Dhat al-Riqa take place?

The books of Sirah (Prophetic biography) mention that the Battle of Dhat al-Riqa (also known as the Battle of Najd) took place in Jumada al-Ula in the the fourth year of the Hijra (some say in Muharram). The Prophet, peace and blessings be upon him, set out to confront the Ghatafan tribes, accompanied by four hundred or seven hundred of the Companions. No fighting occurred in this battle, and the Prophet, peace and blessings be upon him, led the Muslims in the "Salat al-Khawf" (prayer of fear).