diff --git a/superset/db_engine_specs/mssql.py b/superset/db_engine_specs/mssql.py
index 0572319b2cffd..6db01020fb5b0 100644
--- a/superset/db_engine_specs/mssql.py
+++ b/superset/db_engine_specs/mssql.py
@@ -50,18 +50,23 @@ class MssqlEngineSpec(BaseEngineSpec):
 
     _time_grain_expressions = {
         None: "{col}",
-        "PT1S": "DATEADD(second, DATEDIFF(second, '2000-01-01', {col}), '2000-01-01')",
-        "PT1M": "DATEADD(minute, DATEDIFF(minute, 0, {col}), 0)",
-        "PT5M": "DATEADD(minute, DATEDIFF(minute, 0, {col}) / 5 * 5, 0)",
-        "PT10M": "DATEADD(minute, DATEDIFF(minute, 0, {col}) / 10 * 10, 0)",
-        "PT15M": "DATEADD(minute, DATEDIFF(minute, 0, {col}) / 15 * 15, 0)",
-        "PT30M": "DATEADD(minute, DATEDIFF(minute, 0, {col}) / 30 * 30, 0)",
-        "PT1H": "DATEADD(hour, DATEDIFF(hour, 0, {col}), 0)",
-        "P1D": "DATEADD(day, DATEDIFF(day, 0, {col}), 0)",
-        "P1W": "DATEADD(week, DATEDIFF(week, 0, {col}), 0)",
-        "P1M": "DATEADD(month, DATEDIFF(month, 0, {col}), 0)",
-        "P3M": "DATEADD(quarter, DATEDIFF(quarter, 0, {col}), 0)",
-        "P1Y": "DATEADD(year, DATEDIFF(year, 0, {col}), 0)",
+        "PT1S": "DATEADD(SECOND, DATEDIFF(SECOND, '2000-01-01', {col}), '2000-01-01')",
+        "PT1M": "DATEADD(MINUTE, DATEDIFF(MINUTE, 0, {col}), 0)",
+        "PT5M": "DATEADD(MINUTE, DATEDIFF(MINUTE, 0, {col}) / 5 * 5, 0)",
+        "PT10M": "DATEADD(MINUTE, DATEDIFF(MINUTE, 0, {col}) / 10 * 10, 0)",
+        "PT15M": "DATEADD(MINUTE, DATEDIFF(MINUTE, 0, {col}) / 15 * 15, 0)",
+        "PT30M": "DATEADD(MINUTE, DATEDIFF(MINUTE, 0, {col}) / 30 * 30, 0)",
+        "PT1H": "DATEADD(HOUR, DATEDIFF(HOUR, 0, {col}), 0)",
+        "P1D": "DATEADD(DAY, DATEDIFF(DAY, 0, {col}), 0)",
+        "P1W": "DATEADD(DAY, 1 - DATEPART(WEEKDAY, {col}),"
+        " DATEADD(DAY, DATEDIFF(DAY, 0, {col}), 0))",
+        "P1M": "DATEADD(MONTH, DATEDIFF(MONTH, 0, {col}), 0)",
+        "P3M": "DATEADD(QUARTER, DATEDIFF(QUARTER, 0, {col}), 0)",
+        "P1Y": "DATEADD(YEAR, DATEDIFF(YEAR, 0, {col}), 0)",
+        "1969-12-28T00:00:00Z/P1W": "DATEADD(DAY, -1,"
+        " DATEADD(WEEK, DATEDIFF(WEEK, 0, {col}), 0))",
+        "1969-12-29T00:00:00Z/P1W": "DATEADD(WEEK,"
+        " DATEDIFF(WEEK, 0, DATEADD(DAY, -1, {col})), 0)",
     }
 
     custom_errors: Dict[Pattern[str], Tuple[str, SupersetErrorType, Dict[str, Any]]] = {
diff --git a/tests/integration_tests/db_engine_specs/mssql_tests.py b/tests/integration_tests/db_engine_specs/mssql_tests.py
index c14515b27c86a..86310b60c13bd 100644
--- a/tests/integration_tests/db_engine_specs/mssql_tests.py
+++ b/tests/integration_tests/db_engine_specs/mssql_tests.py
@@ -79,7 +79,7 @@ def test_time_exp_mixd_case_col_1y(self):
         col = column("MixedCase")
         expr = MssqlEngineSpec.get_timestamp_expr(col, None, "P1Y")
         result = str(expr.compile(None, dialect=mssql.dialect()))
-        self.assertEqual(result, "DATEADD(year, DATEDIFF(year, 0, [MixedCase]), 0)")
+        self.assertEqual(result, "DATEADD(YEAR, DATEDIFF(YEAR, 0, [MixedCase]), 0)")
 
     def test_convert_dttm(self):
         dttm = self.get_dttm()