diff --git a/src/commands/Article.ts b/src/commands/Article.ts
index 93fcb779..5fe71708 100644
--- a/src/commands/Article.ts
+++ b/src/commands/Article.ts
@@ -172,7 +172,7 @@ export class Article {
 
           let newFileName = `${slugName}${ext}`;
           if (filePrefix && typeof filePrefix === "string") {
-            newFileName = `${format(new Date(), DateHelper.formatUpdate(filePrefix))}-${newFileName}`;
+            newFileName = `${format(new Date(), DateHelper.formatUpdate(filePrefix) as string)}-${newFileName}`;
           }
 
           const newPath = editor.document.uri.fsPath.replace(fileName, newFileName);
@@ -244,7 +244,7 @@ export class Article {
     const dateFormat = Settings.get(SETTING_DATE_FORMAT) as string;
 
     if (dateFormat && typeof dateFormat === "string") {
-      return format(dateValue, DateHelper.formatUpdate(dateFormat));
+      return format(dateValue, DateHelper.formatUpdate(dateFormat) as string);
     } else {
       return typeof dateValue.toISOString === 'function' ? dateValue.toISOString() : dateValue?.toString();
     }
diff --git a/src/commands/Preview.ts b/src/commands/Preview.ts
index 90dd53bc..b38a1764 100644
--- a/src/commands/Preview.ts
+++ b/src/commands/Preview.ts
@@ -35,7 +35,7 @@ export class Preview {
     if (settings.pathname) {
       const articleDate = ArticleHelper.getDate(article);
       try {
-        slug = join(format(articleDate || new Date(), DateHelper.formatUpdate(settings.pathname)), slug);
+        slug = join(format(articleDate || new Date(), DateHelper.formatUpdate(settings.pathname) as string), slug);
       } catch (error) {
         slug = join(settings.pathname, slug);
       }
diff --git a/src/helpers/ArticleHelper.ts b/src/helpers/ArticleHelper.ts
index 8aceac5d..c19ec986 100644
--- a/src/helpers/ArticleHelper.ts
+++ b/src/helpers/ArticleHelper.ts
@@ -204,7 +204,7 @@ export class ArticleHelper {
       let newFileName = `${sanitizedName}.md`;
 
       if (prefix && typeof prefix === "string") {
-        newFileName = `${format(new Date(), DateHelper.formatUpdate(prefix))}-${newFileName}`;
+        newFileName = `${format(new Date(), DateHelper.formatUpdate(prefix) as string)}-${newFileName}`;
       }
       
       newFilePath = join(folderPath, newFileName);
diff --git a/src/helpers/DateHelper.ts b/src/helpers/DateHelper.ts
index f86dc862..b9ae7221 100644
--- a/src/helpers/DateHelper.ts
+++ b/src/helpers/DateHelper.ts
@@ -3,7 +3,11 @@ import { parse, parseISO, parseJSON } from "date-fns";
 
 export class DateHelper {
  
-  public static formatUpdate(value: string) {
+  public static formatUpdate(value: string | null | undefined): string | null {
+    if (!value) {
+      return null;
+    }
+
     value = value.replace(/YYYY/g, 'yyyy');
     value = value.replace(/DD/g, 'dd');
     return value;
diff --git a/src/panelWebView/components/Fields/DateTimeField.tsx b/src/panelWebView/components/Fields/DateTimeField.tsx
index 7d63cf2a..532adfa7 100644
--- a/src/panelWebView/components/Fields/DateTimeField.tsx
+++ b/src/panelWebView/components/Fields/DateTimeField.tsx
@@ -52,7 +52,7 @@ export const DateTimeField: React.FunctionComponent<IDateTimeFieldProps> = ({lab
           selected={dateValue as Date || new Date()}
           onChange={onDateChange}
           timeInputLabel="Time:"
-          dateFormat={format || "MM/dd/yyyy HH:mm"}
+          dateFormat={DateHelper.formatUpdate(format) || "MM/dd/yyyy HH:mm"}
           customInput={(<CustomInput />)}
           showTimeInput
           />