my $l = get_logger( 'base' );

*old = \&Log::Dispatch::FileRotate::time_to_rotate;
*Log::Dispatch::FileRotate::time_to_rotate = sub { return wantarray ? ( 1, 1 ) : 1 };
$l->info('starting up and forcing rotation');
*Log::Dispatch::FileRotate::time_to_rotate = \&old;

$l->info('more logging as usual');