You can try this one.
log4j.appender.appender_name.layout=org.apache.log4j.PatternLayout
log4j.appender.appender_name.layout.ConversionPattern=%d %p [%c] - %m%n
Date params %d. For example : %d{HH:mm:ss,SSS}.
http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/PatternLayout.html