Opinion from members required :-

Suppose a Male whose father,mother & brother are alive.
He is staying away from them , gets married and has three issues ... two daughters & one son..

Date of marriage :-    8th August 1986
Date of Birth of 1st child daughter :-     25th November 1987

His brother is gifting his family a sum of rs 20,000 /= on    19th April 2010.

Now I want to know was he by birth member of his fathers HUF ??

when was his separate HUF constituted ?
date when he got married ?
date of birth of his 1st child ? OR
date when his brother gifted his family Rs.20,000 /= ?

While applying for PAN for H.U.F. --
what will be written in date of creation of H.U.F.
anyone of above mentioned three dates ??  OR 
Ancestral ie. 01-01-0001  ??