diff --git a/rank_progress.py b/rank_progress.py
--- a/rank_progress.py
+++ b/rank_progress.py
@@ -1,13 +1,12 @@
-import sys
 import re
 from itertools import groupby
 from datetime import datetime
 import argparse
 
 parser = argparse.ArgumentParser()
-parser.add_argument("since")
-parser.add_argument("to", default=None)
-parser.add_argument("-c", "--country-code", default="CZ")
+parser.add_argument("since", help="a date in YYYYMMDD format")
+parser.add_argument("to", nargs="?", help="a date in YYYYMMDD format")
+parser.add_argument("-c", "--country-code", default="CZ", help="a two letter country code, default=CZ")
 
 args = parser.parse_args()