Zed is the original pronunciation and is used in all English speaking countries apart from those with an undue American influence on education or too much Sesame Street. Zee is rarely used outside of the US.
The Zee pronunciation is a recent, 17th century phonetic upstart with no possible claims to authenticity or primacy.
Summary: Zed is the original pronunciation and the most common across English speaking countries.
From zed | Search Online Etymology Dictionary (etymonline.com)
zed (n.)
"the name of the letter Z in the alphabet," c. 1400, probably from Old French zede, from Late Latin zeta, from Greek zēta, from Hebrew zayin, letter name, literally "weapon;" so called in reference to the shape of this letter in ancient Hebrew. U.S. pronunciation zee is first attested 1670s. Other dialectal names for the letter are izzard, ezod, uzzard, and zod.
OB
Must make life difficult.Beyond the shores of 'Merica we ALL pronounce Z as Zed (even Canadians)
OB
Must make life difficult.
Instead of "why that?" you can write "yz" only.
My children's alphabet song they sing in school is not the Twinkle Twinkle Little Star one, with a different rhythm and no words except the actual letter names - ending on Zed. I think that rhyming song is also an Americanism.
