Help logwatch and timestamp

Hi,

I'm using logwatch on a new debian 10 install.

i've modified my timestamp in my rsyslog like this
#$ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat
$template MicTemplate,"%$YEAR%-%$MONTH%-%$DAY% 
%timegenerated:12:19:date-rfc3339% %APP-NAME%:%msg%\n"
$ActionFileDefaultTemplate MicTemplate

I've log like this:
2020-02-26 23:16:51 systemd:.....

Logwatch doesn't understand this. How can i patch logwatch to understand 
my template ?

Thanks for help.