diff --git a/package-lock.json b/package-lock.json
index 5d506da..53eb335 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -9,7 +9,6 @@
       "version": "3.2.1",
       "license": "MIT",
       "dependencies": {
-        "date-format": "4.0.3",
         "lodash": "^4.17.21",
         "make-dir": "^3.1.0",
         "xmlbuilder": "^15.1.1"
@@ -1264,14 +1263,6 @@
         "node": ">= 12"
       }
     },
-    "node_modules/date-format": {
-      "version": "4.0.3",
-      "resolved": "https://registry.npmjs.org/date-format/-/date-format-4.0.3.tgz",
-      "integrity": "sha512-7P3FyqDcfeznLZp2b+OMitV9Sz2lUnsT87WaTat9nVwqsBkTzPG3lPLNwW3en6F4pHUiWzr6vb8CLhjdK9bcxQ==",
-      "engines": {
-        "node": ">=4.0"
-      }
-    },
     "node_modules/date-now": {
       "version": "0.1.4",
       "resolved": "https://registry.npmjs.org/date-now/-/date-now-0.1.4.tgz",
@@ -8006,11 +7997,6 @@
       "integrity": "sha512-0R9ikRb668HB7QDxT1vkpuUBtqc53YyAwMwGeUFKRojY/NWKvdZ+9UYtRfGmhqNbRkTSVpMbmyhXipFFv2cb/A==",
       "dev": true
     },
-    "date-format": {
-      "version": "4.0.3",
-      "resolved": "https://registry.npmjs.org/date-format/-/date-format-4.0.3.tgz",
-      "integrity": "sha512-7P3FyqDcfeznLZp2b+OMitV9Sz2lUnsT87WaTat9nVwqsBkTzPG3lPLNwW3en6F4pHUiWzr6vb8CLhjdK9bcxQ=="
-    },
     "date-now": {
       "version": "0.1.4",
       "resolved": "https://registry.npmjs.org/date-now/-/date-now-0.1.4.tgz",
diff --git a/package.json b/package.json
index b9792ee..cf87808 100644
--- a/package.json
+++ b/package.json
@@ -41,7 +41,6 @@
     "time-grunt": "^1.2.1"
   },
   "dependencies": {
-    "date-format": "4.0.3",
     "lodash": "^4.17.21",
     "make-dir": "^3.1.0",
     "xmlbuilder": "^15.1.1"
diff --git a/spec/e2e_spec.js b/spec/e2e_spec.js
index b184f90..81ec5a7 100644
--- a/spec/e2e_spec.js
+++ b/spec/e2e_spec.js
@@ -28,7 +28,7 @@ describe('JUnit Report builder', function () {
     return result.trim();
   };
 
-  const reportWith = (content, testSuitesProperties) => '<?xml version="1.0" encoding="UTF-8"?>\n' + content;
+  const reportWith = (content) => '<?xml version="1.0" encoding="UTF-8"?>\n' + content;
 
   it('should produce a report identical to the expected one', function () {
     builder.testCase().className('root.test.Class1');
diff --git a/src/test_group.js b/src/test_group.js
index a2ae6d1..64eeecb 100755
--- a/src/test_group.js
+++ b/src/test_group.js
@@ -1,6 +1,5 @@
 // @ts-check
 var _ = require('lodash');
-var formatDate = require('date-format').asString;
 var { TestNode } = require('./test_node');
 
 class TestGroup extends TestNode {
@@ -20,7 +19,7 @@ class TestGroup extends TestNode {
    */
   timestamp(timestamp) {
     if (_.isDate(timestamp)) {
-      this._attributes.timestamp = formatDate('yyyy-MM-ddThh:mm:ss', timestamp);
+      this._attributes.timestamp = this.formatDate(timestamp);
     } else {
       this._attributes.timestamp = timestamp;
     }
diff --git a/src/test_node.js b/src/test_node.js
index 7f3ba7d..39152ae 100644
--- a/src/test_node.js
+++ b/src/test_node.js
@@ -104,6 +104,29 @@ class TestNode {
     return element;
   }
 
+  /**
+   * @protected
+   * @param {Date} date
+   * @returns {string}
+   */
+  formatDate(date) {
+    const pad = (num) => (num < 10 ? '0' : '') + num;
+
+    return (
+      date.getFullYear() +
+      '-' +
+      pad(date.getMonth() + 1) +
+      '-' +
+      pad(date.getDate()) +
+      'T' +
+      pad(date.getHours()) +
+      ':' +
+      pad(date.getMinutes()) +
+      ':' +
+      pad(date.getSeconds())
+    );
+  }
+
   /**
    * @protected
    * @param {import('xmlbuilder').XMLElement} element