The German names for the sixth and seventh month are, respectively, "Juni" /'ju:ni/ and "Juli" /'ju:li/.
Since those names are so similar, they can sometimes be mis-heard. As a result, some people say /'ju:no/ ("Juno") and /ju'laI/ ("Julei"? Never seen it in writing) when a distinction must be made. I'm not sure where those names come from, or whether the English name "July", with a similar pronunciation to "Julei", was an influence.
On a related note, there is also a second name for the number "two"—since "zwei" (2) and "drei" (3) also sound fairly similar, the number "2" is sometimes called "zwo", especially in contexts such as spelling out numbers (such as phone numbers) digit-by-digit. This is a bit like the practice I've heard of for using "niner" for 9 in noisy environments such as (ham) radio, to help avoid confusion with "five".