diff --git a/blocklist_scheduler.py b/blocklist_scheduler.py
index 57c30dc..5129dd8 100644
--- a/blocklist_scheduler.py
+++ b/blocklist_scheduler.py
@@ -175,13 +175,16 @@ def schedule_job():
         schedule.every().day.at(f"{hour:02d}:{minute:02d}").do(update_blocklist)
         logging.info(f"Scheduled daily update at {hour:02d}:{minute:02d}")
     elif BLOCKLIST_CRON_TYPE == "weekly":
-        valid_days = ["mon", "tue", "wed", "thu", "fri", "sat", "sun"]
+        day_names = {
+            "mon": "monday", "tue": "tuesday", "wed": "wednesday", "thu": "thursday",
+            "fri": "friday", "sat": "saturday", "sun": "sunday",
+        }
         day = BLOCKLIST_CRON_DAY[:3]
-        if day not in valid_days:
-            logging.error(f"Invalid BLOCKLIST_CRON_DAY '{BLOCKLIST_CRON_DAY}', must be one of {valid_days}. Defaulting to Monday.")
+        if day not in day_names:
+            logging.error(f"Invalid BLOCKLIST_CRON_DAY '{BLOCKLIST_CRON_DAY}', must be one of {list(day_names)}. Defaulting to Monday.")
             day = "mon"
-        getattr(schedule.every(), day).at(f"{hour:02d}:{minute:02d}").do(update_blocklist)
-        logging.info(f"Scheduled weekly update on {day.capitalize()} at {hour:02d}:{minute:02d}")
+        getattr(schedule.every(), day_names[day]).at(f"{hour:02d}:{minute:02d}").do(update_blocklist)
+        logging.info(f"Scheduled weekly update on {day_names[day].capitalize()} at {hour:02d}:{minute:02d}")
     else:
         logging.error(f"Invalid BLOCKLIST_CRON_TYPE '{BLOCKLIST_CRON_TYPE}', must be 'daily' or 'weekly'. Defaulting to daily.")
         schedule.every().day.at(f"{hour:02d}:{minute:02d}").do(update_blocklist)
diff --git a/tests/test_blocklist_scheduler.py b/tests/test_blocklist_scheduler.py
index 3fd64aa..d4a8d26 100644
--- a/tests/test_blocklist_scheduler.py
+++ b/tests/test_blocklist_scheduler.py
@@ -1,4 +1,5 @@
 import pytest
+import schedule as schedule_lib
 
 import blocklist_scheduler as bs
 
@@ -39,3 +40,63 @@ def test_backup_first_start_raises_if_adguard_yaml_missing(tmp_path, monkeypatch
 
     with pytest.raises(FileNotFoundError):
         bs.backup_first_start()
+
+
+# --- schedule_job (schedule) ---
+
+@pytest.fixture(autouse=True)
+def clear_schedule():
+    yield
+    schedule_lib.clear()
+
+
+def test_schedule_job_daily(monkeypatch):
+    monkeypatch.setattr(bs, "BLOCKLIST_CRON_TYPE", "daily")
+    monkeypatch.setattr(bs, "BLOCKLIST_CRON_TIME", "06:00")
+
+    bs.schedule_job()
+
+    assert len(schedule_lib.jobs) == 1
+    job = schedule_lib.jobs[0]
+    assert job.unit == "days"
+    assert str(job.at_time) == "06:00:00"
+    assert job.job_func.func is bs.update_blocklist
+
+
+def test_schedule_job_weekly_valid_day(monkeypatch):
+    monkeypatch.setattr(bs, "BLOCKLIST_CRON_TYPE", "weekly")
+    monkeypatch.setattr(bs, "BLOCKLIST_CRON_TIME", "18:30")
+    monkeypatch.setattr(bs, "BLOCKLIST_CRON_DAY", "wed")
+
+    bs.schedule_job()
+
+    job = schedule_lib.jobs[0]
+    assert job.unit == "weeks"
+    assert job.start_day == "wednesday"
+    assert str(job.at_time) == "18:30:00"
+
+
+def test_schedule_job_weekly_invalid_day_defaults_to_monday(monkeypatch):
+    monkeypatch.setattr(bs, "BLOCKLIST_CRON_TYPE", "weekly")
+    monkeypatch.setattr(bs, "BLOCKLIST_CRON_DAY", "xxx")
+
+    bs.schedule_job()
+
+    assert schedule_lib.jobs[0].start_day == "monday"
+
+
+def test_schedule_job_invalid_time_defaults_to_six_am(monkeypatch):
+    monkeypatch.setattr(bs, "BLOCKLIST_CRON_TYPE", "daily")
+    monkeypatch.setattr(bs, "BLOCKLIST_CRON_TIME", "not-a-time")
+
+    bs.schedule_job()
+
+    assert str(schedule_lib.jobs[0].at_time) == "06:00:00"
+
+
+def test_schedule_job_invalid_type_defaults_to_daily(monkeypatch):
+    monkeypatch.setattr(bs, "BLOCKLIST_CRON_TYPE", "bogus")
+
+    bs.schedule_job()
+
+    assert schedule_lib.jobs[0].unit == "days"