Well you've still got errors there that you have not yet shared.
This query:
UPDATE {$config['tbprefix']}Users
SET U_Birthday = '$NewBday_q',
U_ShowBday = 1
WHERE U_Number = $Number
Should be executing.
You need to actually look at the error logs and see if there's a problem with that query.
You might try updating one manually to see if it produces an error.
Otherwise... I don't know.
Otherwise there's not much else information I can gather from anything posted here to try and help.