How do I set my RollingFileAppender to roll every day?

[Dijkstra30]

I want to set my RollingFileAppender to create a new file every day, not when it reaches to a specific size.
How do i do this in log4j.properties file?

I found suggestions like this:

[COLOR=darkgreen]
log4j.appender.ROLLING.rollingPolicy=TimeBasedRollingPolicy
log4j.appender.ROLLING.rollingPolicy.FileNamePattern=%d.log
[/color]

but i get the warning :
log4j:WARN No such property [rollingPolicy] in org.apache.log4j.RollingFileAppender

Anyone knows what are the properties to be set?