How to clear log files

PostgreSql:8.4.1

Is there a way for me to tell postgres to clear the log file. Example:
I have log files created with names corresponding to the days of the
week. This way they overwrite each other every week. When I deploy
software enhancements I would like to clear the log file for the day
without having to stop postgres. This way anything I see I know was
after the deployment of my enhancements. I tried to just delete the
file with postgres running. I found that it did not recreate the log
file so I was forced to restart postgres.

Is there a command that might clear a log file or force it to rotate?

Thanks,

Lance Campbell

Software Architect/DBA/Project Manager

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