Is there a way to log time format in miliseconds

Greetings,

On log4j2.

I have tried obvious searches and it was immediately clear to me. I'm 
looking for a way to get the time stamp similar to value returned by 
System.currentTimeMillis().

Also want to ensure I can log both human readable and (more) machine 
readable formats based on format string. We have some other log files 
which can't use log4j and just log Sytem.currentTimeMilis as the time 
stamp and it gets very interesting to match timestamps.

Regards,

Niranjan