Fix complaint from new version of mypy

Signed-off-by: M Q <mingmelvinq@nvidia.com>

Author: MMelQin

monai/deploy/operators/dicom_seg_writer_operator.py

@@ -27,6 +27,8 @@
 ImplicitVRLittleEndian, _ = optional_import("pydicom.uid", name="ImplicitVRLittleEndian")
 Dataset, _ = optional_import("pydicom.dataset", name="Dataset")
 FileDataset, _ = optional_import("pydicom.dataset", name="FileDataset")
+DA, _ = optional_import("pydicom.valuerep", name="DA")
+TM, _ = optional_import("pydicom.valuerep", name="TM")
 PyDicomSequence, _ = optional_import("pydicom.sequence", name="Sequence")
 sitk, _ = optional_import("SimpleITK")
 codes, _ = optional_import("pydicom.sr.codedict", name="codes")
@@ -341,8 +343,8 @@ def create_dicom_seg(self, image: np.ndarray, dicom_series: DICOMSeries, output_
         # Adding a few tags that are not in the Dataset
         # Also try to set the custom tags that are of string type
         dt_now = datetime.datetime.now()
-        seg.SeriesDate = dt_now.strftime("%Y%m%d")
-        seg.SeriesTime = dt_now.strftime("%H%M%S")
+        seg.SeriesDate = DA(dt_now.strftime("%Y%m%d"))
+        seg.SeriesTime = TM(dt_now.strftime("%H%M%S"))
         seg.TimezoneOffsetFromUTC = (
             dt_now.astimezone().isoformat()[-6:].replace(":", "")
         )  # '2022-09-27T22:36:20.143857-07:00'