only eprint if more than 1 day

src/main.rs

@@ -164,11 +164,13 @@ fn log(f: &String, enabled: &bool, since: &Option<String>, verbose: &bool, preci
       }
    }
 
+   if result.len() > 1 {
    match precision {
       0 => eprintln!("({:.0}h over {} dates)", total_d, result.len()),
       1 => eprintln!("({:.1}h over {} dates)", total_d, result.len()),
       _ => eprintln!("({:.2}h over {} dates)", total_d, result.len()),
    }
+   }
 
    Ok(())
 }