Jamieson, Fausset and Brown on Ezra 7:8

8. he came to Jerusalem in the fifth month--that is, corresponding to the end of our July or beginning of our August. As he left Babylon on the Jewish New Year's Day (Ezr 7:9), the journey must have occupied not less than four months (a long period), but it was necessary to move at a slow pace and by short, easy stages, as he had to conduct a large caravan of poor people, including women, children, and all their household gear (see on Ezr 8:24).