diff --git a/index.js b/index.js
index a695057..2a7e73c 100644
--- a/index.js
+++ b/index.js
@@ -59,7 +59,7 @@ JWT.sign = function(payload, secretOrPrivateKey, options, callback) {
     payload.iat = payload.iat || timestamp;
   }
 
-  if (options.notBefore) {
+  if (typeof options.notBefore !== 'undefined') {
     payload.nbf = timespan(options.notBefore);
     if (typeof payload.nbf === 'undefined') {
       throw new Error('"notBefore" should be a number of seconds or string representing a timespan eg: "1d", "20h", 60');
@@ -82,7 +82,7 @@ JWT.sign = function(payload, secretOrPrivateKey, options, callback) {
         options.expiresInSeconds;
 
     payload.exp = timestamp + expiresInSeconds;
-  } else if (options.expiresIn) {
+  } else if (typeof options.expiresIn !== 'undefined') {
     payload.exp = timespan(options.expiresIn);
     if (typeof payload.exp === 'undefined') {
       throw new Error('"expiresIn" should be a number of seconds or string representing a timespan eg: "1d", "20h", 60');
@@ -209,8 +209,7 @@ JWT.verify = function(jwtString, secretOrPublicKey, options, callback) {
     if (typeof payload.nbf !== 'number') {
       return done(new JsonWebTokenError('invalid nbf value'));
     }
-    if (payload.nbf >= Math.floor(Date.now() / 1000)) {
-      console.log(payload.nbf, '>=', Math.floor(Date.now() / 1000));
+    if (payload.nbf > Math.floor(Date.now() / 1000)) {
       return done(new NotBeforeError('jwt not active', new Date(payload.nbf * 1000)));
     }
   }
diff --git a/package.json b/package.json
index b6137c0..2e4d122 100644
--- a/package.json
+++ b/package.json
@@ -4,7 +4,7 @@
   "description": "JSON Web Token implementation (symmetric and asymmetric)",
   "main": "index.js",
   "scripts": {
-    "test": "mocha"
+    "test": "mocha --require test/util/fakeDate"
   },
   "repository": {
     "type": "git",
diff --git a/test/jwt.rs.tests.js b/test/jwt.rs.tests.js
index 0c27808..59d7dbe 100644
--- a/test/jwt.rs.tests.js
+++ b/test/jwt.rs.tests.js
@@ -115,6 +115,20 @@ describe('RS256', function() {
       });
     });
 
+
+    it('should valid when date are equals', function(done) {
+      Date.fix(1451908031);
+
+      token = jwt.sign({ foo: 'bar' }, priv, { algorithm: 'RS256', notBefore: 0 });
+
+      jwt.verify(token, pub, function(err, decoded) {
+        assert.isNull(err);
+        assert.isNotNull(decoded);
+        Date.unfix();
+        done();
+      });
+    });
+
     it('should NOT be invalid', function(done) {
       // not active token
       token = jwt.sign({ foo: 'bar' }, priv, { algorithm: 'RS256', notBeforeMinutes: 10 });
diff --git a/test/util/fakeDate.js b/test/util/fakeDate.js
new file mode 100644
index 0000000..d889c82
--- /dev/null
+++ b/test/util/fakeDate.js
@@ -0,0 +1,32 @@
+var oldDate = global.Date;
+
+/*
+ * fix new Date() to a fixed unix timestamp.
+ */
+global.Date.fix = function (timestamp) {
+  var time = timestamp * 1000;
+
+  if (global.Date.unfake) {
+    global.Date.unfake();
+  }
+
+  global.Date = function (ts) {
+    return new oldDate(ts || time);
+  };
+
+  global.Date.prototype = Object.create(oldDate.prototype);
+  global.Date.prototype.constructor = global.Date;
+
+  global.Date.prototype.now = function () {
+    return time;
+  };
+
+  global.Date.now = function () {
+    return time;
+  };
+
+  global.Date.unfix = function () {
+    global.Date = oldDate;
+  };
+
+};
\ No newline at end of file