How to set timezone to UTC in Play Framework 2.0 f

Question

We'd like our Play Framework 2.0 Scala applications to handle all date and time information in UTC, both in the app servers and in MySQL database servers.

The trick is:

• Without changing deployment environment
• Without changing CI (testing) environment
• Without changing local (dev) environment

Is there a standard best practice to do this? We want the tests to run in UTC, without having to pass -Duser.timezone=GMT on all commandlines. Ditto for bringing up servers with play start.

Answer 1

This was easier than we'd expected.

First, in application.conf, configure the JDBC URL with the parameters as described on another StackOverflow question:

# Set MySQL Connector/J to use UTC server connection and time conversions
#   see https://stackoverflow.com/questions/10488529/gettimestamp-does-timezone-converstion-twice-in-mysql-jdbc-connector
db.default.url="jdbc:mysql://localhost/database?useGmtMillisForDatetimes=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&useTimezone=true&serverTimezone=UTC"

Second, in Build.scala, set the Java system property and the default:

// Setting this property here forces the JVM to run in UTC time, 
// both for test (`play test`) and development (`play start`) modes, 
// but not for production (`play dist`).
System.setProperty("user.timezone", "GMT")
TimeZone.setDefault(TimeZone.getTimeZone("GMT"))

These two changes together will handle both test (play test) and development (play start) modes.

For production (play dist), one must still set the property before launch. For example, by:

1. Editing the generated start script to add export _JAVA_OPTIONS=-Duser.timezone=GMT
2. Invoking the start script with -Duser.timezone=GMT
3. Launching within an existing JVM after calling System.setProperty("user.timezone", "GMT")