James Hay, 15th Earl of Erroll
James Hay, 15th Earl of Erroll (20 April 1726 – 3 July 1778) was a Scottish nobleman and the son of William Boyd, 4th Earl of Kilmarnock.
Simon Abney-Hastings, 15th Earl of Loudoun
Simon Michael Abney- Hastings, 15th Earl of Loudoun( born 29 October 1974), is a British aristocrat living in Australia who is the current holder of the ancient Scottish noble title of Earl of Loudoun.
David Douglas-Home, 15th Earl of Home
David Alexander Cospatrick Douglas- Home, 15th Earl of Home,( born 20 November 1943) is a British businessman and Conservative politician.
William Herbert, 18th Earl of Pembroke
William Alexander Sidney Herbert, 18th Earl of Pembroke, 15th Earl of Montgomery( born 18 May 1978) is an English peer.
He became earl in 2003 following the death of his father, Henry Herbert, 17th Earl of Pembroke.
Toni Arthur
Toni Arthur- Hay( born 27 December 1940) is an English theatre director, former folk singer and television presenter.
William Hay, 15th Earl of Kinnoull
Arthur William George Patrick Hay, 15th Earl of Kinnoull (26 May 1935 – 7 June 2013), styled as Viscount Dupplin until age 3, was a hereditary peer, surveyor, farmer, and member of the House of Lords.
His titles were Earl of Kinnoull, Viscount Dupplin and Lord Hay of Kinfauns in the Peerage of Scotland; and Baron Hay of Pedwardine in the Peerage of Great Britain.
Arthur Hay, 9th Marquess of Tweeddale
Colonel Arthur Hay, 9th Marquess of Tweeddale FRS FRSE FZS( 9 November 1824 – 29 December 1878), known before 1862 as Lord Arthur Hay and between 1862 and 1876 as Viscount Walden, was a Scottish soldier and ornithologist.
George Hay, 14th Earl of Kinnoull
George Harley Hay, 14th Earl of Kinnoull (30 March 1902 – 19 March 1938), styled as Viscount Dupplin from 1903 to 1916, was a Scottish peer.
His titles were Earl of Kinnoull, Viscount Dupplin and Lord Hay of Kinfauns in the Peerage of Scotland; and Baron Hay of Pedwardine in the Peerage of Great Britain.
George Montgomerie, 15th Earl of Eglinton
George Arnulph Montgomerie, 15th Earl of Eglinton, 3rd Earl of Winton( 23 February 1848 – 10 August 1919) was the third and youngest son of Archibald Montgomerie, 13th Earl of Eglinton and his first wife, Theresa Newcomen.
John Boyle, 15th Earl of Cork
John Richard Boyle, 15th Earl of Cork and 15th Earl of Orrery( born 3 November 1945) is a British hereditary peer and a member of the House of Lords, where he sits as a Crossbencher.
Boyle was an officer in the Royal Navy before inheriting his titles in 2003.

Question: When is William Hay, 15Th Earl Of Kinnoull's father's birthday?
Answer: 30 March 1902