adding position info & updated testcase

Author: dannyi96

pandas/_libs/tslib.pyx

@@ -824,7 +824,8 @@ cdef _array_to_datetime_object(
                                                    yearfirst=yearfirst)
                     pydatetime_to_dt64(oresult[i], &dts)
                     check_dts_bounds(&dts)
-            except (ValueError, OverflowError):
+            except (ValueError, OverflowError) as ex:
+                ex.args = (str(ex) + f" present at position {i}", )
                 if is_coerce:
                     oresult[i] = <object>NaT
                     continue

pandas/tests/tools/test_to_datetime.py

@@ -2593,7 +2593,7 @@ def test_invalid_origins_tzinfo(self):
 
     def test_incorrect_value_exception(self):
         # GH47495
-        with pytest.raises(ValueError, match="Unknown string format: today"):
+        with pytest.raises(ValueError, match="Unknown string format: yesterday present at position 1"):
             to_datetime(["today", "yesterday"])
 
     @pytest.mark.parametrize("format", [None, "%Y-%m-%d %H:%M:%S"])