"Hajj is (to be observed in) the specified months. Whoever shall observe Hajj in them (the
specified months) shall refrain from sexual intercourse, misconduct, and arguments throughout Hajj."
As the above words clearly indicate, God allowed Hajj to be observed any time within the specified (four) months which are called "Hurum" (9:36). However, the Muslims today refuse this concession and limit their Hajj to only the first ten days of the month of Zhu Al-Hijjah!
For full details of how to observe Hajj according to the Quran, please go to the following page: Hajj, the Quranic way