I understand that the newborn baby's hair should be shaved 0n the 7th day of his birth. But what if I would like to do his Aqeeqah later when I go to my native place on vacation. Do I have to shave the head of my son again on that same day i.e. Aqeeqah. Or shaving head one's is enough after birth.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

First of all, shaving the hair of the new-born is something desirable and not obligatory. It is desirable that this is done on the seventh day of his birth. The Prophet said: "Every child bonds to his/her 'Aqeeqah, (i.e. his dutifulness to parents and him being protected by Allaah and blessed is subject to his parents, slaughtering) which should be done on the seventh day (after the birth), and on that day he (she) should be named and his (her) hair should be shaved off." [Abu Daawood] It is sufficient to shave his hair once even if the slaughtering of the 'Aqeeqah is delayed. It is recommended that the slaughtering is done on the seventh day, if not, on the fourteenth day, and if not, on the twenty-first day. One should not delay the 'Aqeeqah without any need.  

Allaah Knows best.