diff --git a/biscuit/apps/chronos/util.py b/biscuit/apps/chronos/util.py
index 88b010dc0b358ac245e3b4f7fcf963dee3ad9662..9781ac55e9ee583316b36b112cfee652ad9da152 100644
--- a/biscuit/apps/chronos/util.py
+++ b/biscuit/apps/chronos/util.py
@@ -37,4 +37,4 @@ def week_weekday_from_date(when: date) -> Sequence[int]:
 
 
 def week_weekday_to_date(week: int, weekday: int) -> date:
-    return week_days(week)[weekday]
+    return week_days(week)[weekday-1]