DoB from the Civil Birth in the IGI:
Alfred Edgar Boyd    Birth: 25 MAY 1879  Aghadowey, Londonderry, Ireland Parents: Father: John Boyd Mother: Jane Mc Alister.
Confirmed by baptism registry of Aghadowey Presbyterian Church.      

DoD from headstone in Aghadowey Presbyterian Church: "died 25 July 1936, aged 59 years".

DoB from her gravestone in Aghadowey Presbyterian Church: Margaret Elizabeth, died 30 January 1961, aged 79 years
 

DoD from her gravestone in Aghadowey Presbyterian Church:Margaret Elizabeth, died 30 January 1961, aged 79 years

DoB from gravestone.

DoD from gravestone in Aghadowey Presbyterian Church as transcribed by Lavonne on the Bann Valley site.

DoB from LG

DoB from gravestone.

DoD from gravestone in Aghadowey Presbyterian Church as transcribed by Lavonne on the Bann Valley site.

DoB from Ali Gallup.

DoB from Ali Gallup.

DoD from gravestone in Aghadowey Presbyterian Church as transcribed by Lavonne on the Bann Valley site.

DoB from Ali Gallup.

DoD from gravestone in Aghadowey Presbyterian Church as transcribed by Lavonne on the Bann Valley site.

DoB from obituary.

Civil Birth Record (from IFHF)
Name:    Ringland Gilmore Boyd    
Date of Birth:    01-Jan-1917
Date of Baptism:    1-Jan-0
Address:    Cullycapple    
Parish/District:    AGHADOWEY
Gender:     Male    
County    Co. Derry
Denomination:    
Registrar District
Father:    Alfred Edgar Boyd    
Mother:    Margaret Elizabeth Archibald
Occupation:    School Teacher    
Sponsor 1 /
Informant 1:    Alfred Edgar Boyd    Sponsor 2 /
Informant 2:    

DoD and details taken from his obituary.  He was killed in a car accident at Horns Hill, near Cambridge in Gloucestershire on the Gloucester-Bristol road "on the eve of his annual summer holiday, which he intended spending with his fiancee at his mother's home in Aghadowey" (although his mother's home was at "Finvola", Coleraine Road, Garvagh when he died, she was probably from Aghadowey originally and in fact, his DoB says he was born in Cullycapple, Aghadowey).

109 Boyd-Gilmore-KennedyCage
In loving memory of
Alfred Edgar Boyd, died 25 July 1936, aged 59 years
and his wife, Margaret Elizabeth, died 30 January 1961, aged 79 years
and their son, Ringland Gilmore, Lt. Co., M.C.R.A.M.C., died 17 August 1950. aged 33 years
also their daughter, Anna Christina, died 9 July, 1974, aged 63 years
their granddaughters
Trudy and Katie, 1939 and 1981
Kathleen Bryce Kennedy Cage, nee Boyd, died 6 October 1982, aged 70 years
Horace Arthur James Cage, died 12 November 1986, aged 84 years

England & Wales, Death Index, 1916-2006 about Ringland G Boyd
Name:    Ringland G Boyd
Birth Date:    abt 1917
Date of Registration:    Jul-Aug-Sep 1950
Age at Death:    33
Registration district:    Gloucester City
Inferred County:    Gloucestershire
Volume:    7b
Page:    349

This is odd:
England & Wales, National Probate Calendar (Index of Wills and Administrations), 1858-1966 about Ringland Gilmore Boyd
Name:    Ringland Gilmore Boyd
Probate Date:    28 Dec 1950
Death Date:    17 Aug 1950
Death Place:    Gloucestershire, England
Registry:    Gloucestershire, England
Hi Jill,
I hope you and family are well, and Margaret too and that you are all looking forward to Christmas.
I found the attached at Ancestry.com and it is more than a little puzzling as it says that your Mum-in-law was actually married to Ringland at the time of his death.
I am sure this is him even though the death date is wrong.  Ringland Gilmore Boyd continues to be an enigma!
What do you think?

DoB from Ali Gallup.