Here is my answer. From, Quran: a Reformist Translation, note on verse 9:37:
009:037 Today's Sunni and Shiite mushriks consider Rajab, Zul-Qada, Zul-Hijja, and Muharram to be the Restricted Months (the 7th, 11th, 12th, and 1st months of lunar calendar). However, when we study 2:197,217; 9:2,5,36 and the names of known months, we will discover that real Restricted Months must be four consecutive months and they are Zul-Hijja, Muharram, Safar, Rabi ul-Awal (12th, 1st, 2nd, and 3rd months). The very name of the 12th month, Zul-Hijja (Contains Haj), gives us a clue that it is the first month of haj pilgrimage. When we start from the 12th month, the last of the Restricted Months becomes the 3rd month, Rabi ul-Awal (First Fourth), and the very name of this month also is revealing; it suggests that it is the fourth month of the Restricted Months. Then, why the qualification "First"? Well, the name of the following month provides an explanation: Rabi ul-Akhir (Second Fourth), which is the fourth month from the beginning of the year. In other words we have two months called "Fourth," the first one referring to the fourth restricted moth, with the second fourth referring to the fourth month of the lunar year. The word rabi (fourth) is used for seasons because each season is one fourth of a year. It is interesting that many of the crimes and distortions mentioned in the Quran have been committed by those who have abandoned the Quran for the sake of hadith and sunna; they repeated the same blunder of their polytheist ancestors.