US layout keyboards have them on the same button as tilde: ~ in the top left, underneath the ESC button.
So your query would be:
UPDATE users SET `DATE` = (SELECT `DATE` FROM users WHERE uID = '2637') WHERE uID = '10576';
(I haven't tested this, so I don't know if it works)
But, as Guido mentions, it's best not to use column names that are reserved words in MySQL.