MySQL and debian-sys-maint account

If for some reason your debian-sys-maint account is unset in MySQL, during MySQL start you will have connect to server error. You might need to set this account in the MySQL server itself.
cat /etc/mysql/debian.cnf to get the password value from the file.
Then connect to the DB
mysql -u root -p
and execute:
GRANT ALL PRIVILEGES ON *.* TO 'debian-sys-maint'@'localhost' IDENTIFIED BY 'YOUR_PASSWORD' WITH GRANT OPTION

Changing time on CentOS

just copy relevant timezone file from /usr/share/zoneinfo to /etc/localtime

like:
cp /usr/share/zoneinfo/Europe/Moscow /etc/localtime