fix: cannot perform storeDest (split undefined)

# Problems
- StudyTime maybe empty cause `startedDate`'s value is "1234undefined"
- that cannot convert to Date type

# Solutions
- Use only study date to get year and month,
because study time may be empty
- and we just need the year and month

api/dicom-web/stow/service/stow.js

@@ -201,18 +201,20 @@ function detachBigValuesDicomJson(dicomJson) {
  * @param {Object} dicomJson
  */
 function getStoreDest(dicomJson) {
-    let startedDate = "";
-    startedDate =
-        dcm2jsonV8.dcmString(dicomJson, "00080020") +
-        dcm2jsonV8.dcmString(dicomJson, "00080030");
-    if (!startedDate) startedDate = Date.now();
-    startedDate = moment(startedDate, "YYYYMMDDhhmmss").toISOString();
-    let startedDateSplit = startedDate.split("-");
-    let year = startedDateSplit[0];
-    let month = startedDateSplit[1];
-    let uid = dcm2jsonV8.dcmString(dicomJson, "0020000E");
-    let shortUID = sh.unique(uid);
-    let relativeStorePath = `files/${year}/${month}/${shortUID}/`;
+    let studyDate = dcm2jsonV8.dcmString(dicomJson, "00080020");
+    let studyDateString;
+    if (!studyDate) {
+        studyDateString = moment().format("YYYY-MM-DD");
+    } else {
+        studyDateString = moment(studyDate, "YYYYMMDD").format("YYYY-MM-DD");
+    }
+    let studyDateSplit = studyDateString.split("-");
+    let year = studyDateSplit[0];
+    let month = studyDateSplit[1];
+    let seriesUID = dcm2jsonV8.dcmString(dicomJson, "0020000E");
+    let shortSeriesUID = sh.unique(seriesUID);
+
+    let relativeStorePath = `files/${year}/${month}/${shortSeriesUID}/`;
     let fullStorePath = path.join(
         process.env.DICOM_STORE_ROOTPATH,
         relativeStorePath