How to identify legality of a child?

A child that is born after the two years from the time of ending of marriage is legal. That principle is mentioned in the following judgment below:-

                                                                       

  Citation Name  : 2008  SCMR  1707     SUPREME-COURT

  Side Appellant : SHARAFAT ALI ASHRAF

  Side Opponent : ADDITIONAL DISTRICT JUDGE, BAHAWALPUR

                       

                        Parentage---Acknowledgement---Legitimacy---child  born during the continuance of a valid marriage and not earlier than the expiration of six lunar months from the date of such marriage or within a period of two years after the dissolution of the marriage, shall be the conclusive proof that the child  so born is the legitimate child  of the spouses provided the mother remained unmarried---In the present case, there was no evidence or proof whatsoever to affirm that minor was born after divorce, nor any evidence existed on record that mother of the minor had been living in adultery and the minor was being disowned by the father with sole object and intention of 'avoiding the liability to maintain the minor child ---Minor having born out of the wedlock between both the spouses, would inevitably be deemed to be a legitimate child  and as such lawfully entitled to be supported by the father.