Some background:
I have a Java 1.6 webapp running on Tomcat 7. The database is MySQL 5.5. Previously, I was using Mysql JDBC driver 5.1.23 to connect to the DB. Ever
There is no impact of setting server time as UTC (for instance with jdbc:mysql://localhost:3306/myschema?serverTimezone=UTC, even if your application/database servers are not in this timezone. The important is for the application connection string + database to be synchronized with the same time zone.
In other words, simply setting serverTimezone=UTC with a different time zone on the database server will shift any dates extracted from the database