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Signed-off-by: Victor Garcia Reolid <victor@seita.nl>

timely_beliefs/sensors/func_store/knowledge_horizons.py

@@ -55,11 +55,16 @@ def x_years_ago_at_date(
                             These bounds are normally useful for creating more efficient database queries when filtering by belief time.
     """
 
-    if x < 0:
-        raise ValueError("Negative value for `x` not supported.")
+    MAX_DAYS_IN_A_YEAR = 366
+    MIN_DAYS_IN_A_YEAR = 366
+
+    if x <= 0:
+        raise ValueError("Only positive values for `x` are supported.")
 
     if get_bounds:
-        return timedelta(days=(x - 1) * 366 - 3), timedelta(days=(x + 1) * 366 + 1)
+        # The minimum corresponds to an event at the 1st of January and a reference on the 31st of December on the the year `x` years ago.
+        # The maximum correponds to an event on the 31st of December and a reference on the 1st of January on the year `x` years ago.
+        return timedelta(days=(x - 1) * MIN_DAYS_IN_A_YEAR), timedelta(days=(x + 1) * MAX_DAYS_IN_A_YEAR + 1)
 
     if isinstance(event_start, datetime):
         return x_years_ago_at_date_datetime(event_start, day, month, x, z)

timely_beliefs/sensors/func_store/test_knowledge_horizons.py

@@ -152,7 +152,7 @@ def test_x_years_ago_at_date():
         datetime(2024, 12, 31, 23, 59, 59, tzinfo=utc),
     ],
 )
-@pytest.mark.parametrize("year", list(range(6)))
+@pytest.mark.parametrize("year", list(range(1,6)))
 def test_x_years_ago_at_date_bounds(event_start, year):
     knowledge_func_params = dict(month=12, day=31, x=year)