Calendar* Correction: Black Sabbath

Numerous websites report that Black Sabbath performed in public for the first time on July 13, 1968 in Birmingham, England.  These reports are false in every sense of the word.

A group containing future Sabbath members Tony Iommi and drummer Bill Ward did play a gig on July 13, 1968, but the group was called Mythology, not Black Sabbath.  This was not Mythology's first gig--they had been together since 1966 and had played several concerts around the region, and Iommi had been with the band since January, with Ward joining in mid-February. 

Actually, the show referred to was Mythology's last gig before breaking up.  Iommi and Ward formed with lead singer Ozzy Osbourne and bassist Terry "Geezer" Butler and two other members, but that group was called the Polka Tulk Blues Band.  They didn't become Black Sabbath until after another name change to the group Earth and personnel changes as well.   

This information is taken from the official website of Black Sabbath, confirmed by numerous sources.  The website owners who print that the group performed its first public concert on July 13, 1968 should read it.