diff --git a/index.js b/index.js
index 6672a8967..c3dc4ee7f 100644
--- a/index.js
+++ b/index.js
@@ -55,6 +55,9 @@ module.exports = {
         convertToXml: require('./lib/s3middleware/convertToXml'),
         escapeForXml: require('./lib/s3middleware/escapeForXml'),
         tagging: require('./lib/s3middleware/tagging'),
+        checkDateModifiedHeaders:
+            require('./lib/s3middleware/validateConditionalHeaders')
+            .checkDateModifiedHeaders,
         validateConditionalHeaders:
             require('./lib/s3middleware/validateConditionalHeaders')
             .validateConditionalHeaders,
diff --git a/lib/s3middleware/validateConditionalHeaders.js b/lib/s3middleware/validateConditionalHeaders.js
index 38cfb55a5..4a0eba2b0 100644
--- a/lib/s3middleware/validateConditionalHeaders.js
+++ b/lib/s3middleware/validateConditionalHeaders.js
@@ -68,6 +68,31 @@ function _checkUnmodifiedSince(ifUnmodifiedSinceTime, lastModified) {
     return res;
 }
 
+/**
+ * checks 'if-modified-since' and 'if-unmodified-since' headers if included in
+ * request against last-modified date of object
+ * @param {object} headers - headers from request object
+ * @param {string} lastModified - last modified date of object
+ * @return {object} contains modifiedSince and unmodifiedSince res objects
+ */
+function checkDateModifiedHeaders(headers, lastModified) {
+    let lastModifiedDate = new Date(lastModified);
+    lastModifiedDate.setMilliseconds(0);
+    lastModifiedDate = lastModifiedDate.getTime();
+
+    const ifModifiedSinceHeader = headers['if-modified-since'] ||
+        headers['x-amz-copy-source-if-modified-since'];
+    const ifUnmodifiedSinceHeader = headers['if-unmodified-since'] ||
+        headers['x-amz-copy-source-if-unmodified-since'];
+
+    const modifiedSinceRes = _checkModifiedSince(ifModifiedSinceHeader,
+        lastModifiedDate);
+    const unmodifiedSinceRes = _checkUnmodifiedSince(ifUnmodifiedSinceHeader,
+        lastModifiedDate);
+
+    return { modifiedSinceRes, unmodifiedSinceRes };
+}
+
 /**
  * validateConditionalHeaders - validates 'if-modified-since',
  * 'if-unmodified-since', 'if-match' or 'if-none-match' headers if included in
@@ -79,23 +104,14 @@ function _checkUnmodifiedSince(ifUnmodifiedSinceTime, lastModified) {
  * empty object if no error
  */
 function validateConditionalHeaders(headers, lastModified, contentMD5) {
-    let lastModifiedDate = new Date(lastModified);
-    lastModifiedDate.setMilliseconds(0);
-    lastModifiedDate = lastModifiedDate.getTime();
     const ifMatchHeader = headers['if-match'] ||
         headers['x-amz-copy-source-if-match'];
     const ifNoneMatchHeader = headers['if-none-match'] ||
         headers['x-amz-copy-source-if-none-match'];
-    const ifModifiedSinceHeader = headers['if-modified-since'] ||
-        headers['x-amz-copy-source-if-modified-since'];
-    const ifUnmodifiedSinceHeader = headers['if-unmodified-since'] ||
-        headers['x-amz-copy-source-if-unmodified-since'];
     const etagMatchRes = _checkEtagMatch(ifMatchHeader, contentMD5);
     const etagNoneMatchRes = _checkEtagNoneMatch(ifNoneMatchHeader, contentMD5);
-    const modifiedSinceRes = _checkModifiedSince(ifModifiedSinceHeader,
-        lastModifiedDate);
-    const unmodifiedSinceRes = _checkUnmodifiedSince(ifUnmodifiedSinceHeader,
-        lastModifiedDate);
+    const { modifiedSinceRes, unmodifiedSinceRes } =
+        checkDateModifiedHeaders(headers, lastModified);
     // If-Unmodified-Since condition evaluates to false and If-Match
     // is not present, then return the error. Otherwise, If-Unmodified-Since is
     // silent when If-Match match, and when If-Match does not match, it's the
@@ -120,5 +136,6 @@ module.exports = {
     _checkEtagNoneMatch,
     _checkModifiedSince,
     _checkUnmodifiedSince,
+    checkDateModifiedHeaders,
     validateConditionalHeaders,
 };
diff --git a/tests/unit/s3middleware/validateConditionalHeaders.js b/tests/unit/s3middleware/validateConditionalHeaders.js
index e38e762f1..8ed21dd87 100644
--- a/tests/unit/s3middleware/validateConditionalHeaders.js
+++ b/tests/unit/s3middleware/validateConditionalHeaders.js
@@ -7,6 +7,7 @@ const {
     _checkEtagNoneMatch,
     _checkModifiedSince,
     _checkUnmodifiedSince,
+    checkDateModifiedHeaders,
     validateConditionalHeaders,
 } = require('../../../lib/s3middleware/validateConditionalHeaders');
 
@@ -172,6 +173,59 @@ describe('validateConditionalHeaders util function ::', () => {
     });
 });
 
+describe('checkDateModifiedHeaders util function: ', () => {
+    const expectedSuccess = {
+        present: true,
+        error: null,
+    };
+
+    const expectedAbsense = {
+        present: false,
+        error: null,
+    };
+
+    it('should return NotModified error for \'if-modified-since\' header',
+    () => {
+        const header = {};
+        header['if-modified-since'] = afterLastModified;
+        const { modifiedSinceRes, unmodifiedSinceRes } =
+            checkDateModifiedHeaders(header, lastModified);
+        assert.deepStrictEqual(modifiedSinceRes.error, errors.NotModified);
+        assert.deepStrictEqual(unmodifiedSinceRes, expectedAbsense);
+    });
+
+    it('should return PreconditionFailed error for \'if-unmodified-since\' ' +
+    'header', () => {
+        const header = {};
+        header['if-unmodified-since'] = beforeLastModified;
+        const { modifiedSinceRes, unmodifiedSinceRes } =
+            checkDateModifiedHeaders(header, lastModified);
+        assert.deepStrictEqual(unmodifiedSinceRes.error,
+            errors.PreconditionFailed);
+        assert.deepStrictEqual(modifiedSinceRes, expectedAbsense);
+    });
+
+    it('should succeed if \'if-modified-since\' header value is earlier ' +
+    'than last modified', () => {
+        const header = {};
+        header['if-modified-since'] = beforeLastModified;
+        const { modifiedSinceRes, unmodifiedSinceRes } =
+            checkDateModifiedHeaders(header, lastModified);
+        assert.deepStrictEqual(modifiedSinceRes, expectedSuccess);
+        assert.deepStrictEqual(unmodifiedSinceRes, expectedAbsense);
+    });
+
+    it('should succeed if \'if-unmodified-since\' header value is later ' +
+    'than last modified', () => {
+        const header = {};
+        header['if-unmodified-since'] = afterLastModified;
+        const { modifiedSinceRes, unmodifiedSinceRes } =
+            checkDateModifiedHeaders(header, lastModified);
+        assert.deepStrictEqual(unmodifiedSinceRes, expectedSuccess);
+        assert.deepStrictEqual(modifiedSinceRes, expectedAbsense);
+    });
+});
+
 describe('_checkEtagMatch function :', () => {
     const expectedSuccess = {
         present: true,