diff --git a/dist/base/BaseClient.js b/dist/base/BaseClient.js
index f0cd869..3ddc73b 100644
--- a/dist/base/BaseClient.js
+++ b/dist/base/BaseClient.js
@@ -8,13 +8,8 @@ const getSignedParams = require('../lib/sign.js').getSignedParams;
 
 const fetch = require('../lib/fetch.js');
 
-const dayjs = require('dayjs');
-
-const utc = require('dayjs/plugin/utc.js');
-
 const qs = require('qs');
 
-dayjs.extend(utc);
 module.exports = class BaseClient {
   constructor(clientConfig) {
     _defineProperty(this, "_baseConfig", {});
@@ -43,7 +38,7 @@ module.exports = class BaseClient {
       Service: this._baseConfig.config.credentials.service,
       Action: apiAction,
       Version: apiConfig.config.query.Version,
-      Timestamp: dayjs().utc().format('YYYY-MM-DDThh:mm:ss') + 'Z',
+      Timestamp: new Date().toISOString().replace(/\.\d{3}Z$/, 'Z'),
       SignatureVersion: '1.0',
       SignatureMethod: 'HMAC-SHA256',
       Region: this.region || this._baseConfig.config.credentials.region
diff --git a/package-lock.json b/package-lock.json
index be68f40..691b9a1 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -12,7 +12,6 @@
                 "abort-controller": "^3.0.0",
                 "core-js": "^3.6.5",
                 "crypto-js": "^4.1.1",
-                "dayjs": "^1.10.7",
                 "node-fetch": "^2.6.7",
                 "qs": "^6.10.3"
             },
@@ -2223,11 +2222,6 @@
             "resolved": "https://registry.npmmirror.com/crypto-js/-/crypto-js-4.1.1.tgz",
             "integrity": "sha512-o2JlM7ydqd3Qk9CA0L4NL6mTzU2sdx96a+oOfPu8Mkl/PK51vSyoi8/rQ8NknZtk44vq15lmhAj9CIAGwgeWKw=="
         },
-        "node_modules/dayjs": {
-            "version": "1.10.8",
-            "resolved": "https://registry.npmmirror.com/dayjs/-/dayjs-1.10.8.tgz",
-            "integrity": "sha512-wbNwDfBHHur9UOzNUjeKUOJ0fCb0a52Wx0xInmQ7Y8FstyajiV1NmK1e00cxsr9YrE9r7yAChE0VvpuY5Rnlow=="
-        },
         "node_modules/debug": {
             "version": "4.3.3",
             "resolved": "https://registry.npmmirror.com/debug/-/debug-4.3.3.tgz",
@@ -5478,11 +5472,6 @@
             "resolved": "https://registry.npmmirror.com/crypto-js/-/crypto-js-4.1.1.tgz",
             "integrity": "sha512-o2JlM7ydqd3Qk9CA0L4NL6mTzU2sdx96a+oOfPu8Mkl/PK51vSyoi8/rQ8NknZtk44vq15lmhAj9CIAGwgeWKw=="
         },
-        "dayjs": {
-            "version": "1.10.8",
-            "resolved": "https://registry.npmmirror.com/dayjs/-/dayjs-1.10.8.tgz",
-            "integrity": "sha512-wbNwDfBHHur9UOzNUjeKUOJ0fCb0a52Wx0xInmQ7Y8FstyajiV1NmK1e00cxsr9YrE9r7yAChE0VvpuY5Rnlow=="
-        },
         "debug": {
             "version": "4.3.3",
             "resolved": "https://registry.npmmirror.com/debug/-/debug-4.3.3.tgz",
diff --git a/package.json b/package.json
index eee2b71..255de76 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,6 @@
         "abort-controller": "^3.0.0",
         "core-js": "^3.6.5",
         "crypto-js": "^4.1.1",
-        "dayjs": "^1.10.7",
         "node-fetch": "^2.6.7",
         "qs": "^6.10.3"
     },
diff --git a/src/base/BaseClient.js b/src/base/BaseClient.js
index bccf3ab..f856de1 100644
--- a/src/base/BaseClient.js
+++ b/src/base/BaseClient.js
@@ -1,11 +1,7 @@
 const getSignedParams = require('../lib/sign.js').getSignedParams
 const fetch = require('../lib/fetch.js')
-const dayjs = require('dayjs')
-const utc = require('dayjs/plugin/utc.js')
 const qs = require('qs')
 
-dayjs.extend(utc)
-
 module.exports = class BaseClient {
     _baseConfig = {}
     _apiList = {}
@@ -32,7 +28,7 @@ module.exports = class BaseClient {
             Service: this._baseConfig.config.credentials.service,
             Action: apiAction,
             Version: apiConfig.config.query.Version,
-            Timestamp: dayjs().utc().format('YYYY-MM-DDThh:mm:ss')+'Z',
+            Timestamp: (new Date()).toISOString().replace(/\.\d{3}Z$/, 'Z'),
             SignatureVersion: '1.0',
             SignatureMethod: 'HMAC-SHA256',
             Region: this.region || this._baseConfig.config.credentials.region,
@@ -89,4 +85,4 @@ module.exports = class BaseClient {
         }
         return JSON.stringify(signedParams)
     }
-}
\ No newline at end of file
+}