diff --git a/dev-requirements.txt b/dev-requirements.txt
index 6364219..6b74877 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -1,3 +1,5 @@
 bandit==1.4.0
 flake8==3.3.0
+freezegun==0.3.9
+requests==2.16.5
 safety==0.5.1
diff --git a/tests/test_consts.py b/tests/test_consts.py
new file mode 100644
index 0000000..7bbbe9b
--- /dev/null
+++ b/tests/test_consts.py
@@ -0,0 +1,105 @@
+from tests import BaseTestCase
+from md_pdf import consts
+from unittest import skipIf
+import os
+import requests
+import datetime
+from freezegun import freeze_time
+
+
+class ConstsTestCase(BaseTestCase):
+    def setUp(self):
+        super().setUp()
+        self.this_dir = os.path.dirname(__file__)
+        self.project_root = os.path.normpath(os.path.join(self.this_dir, '..'))
+
+    def test_project_dir(self):
+        self.assertEqual(
+            consts.PROJECT_DIR,
+            os.path.normpath(os.path.join(self.this_dir, '..', 'md_pdf'))
+        )
+        self.assertIn(consts.WORKING_DIR, consts.PROJECT_DIR)
+
+    def test_working_dir(self):
+        self.assertEqual(consts.WORKING_DIR, self.project_root)
+
+    @skipIf('APPDATA' not in os.environ, 'not on windows')
+    def test_windows_asset_dir(self):
+        self.assertIn(os.environ['APPDATA'], consts.ASSETS_DIR)
+
+    @skipIf('HOME' not in os.environ, 'not on windows')
+    def test_asset_dir(self):
+        self.assertEqual(consts.ASSETS_DIR, os.path.expanduser('~/.mdp'))
+
+    def test_csl_dir(self):
+        self.assertIn(consts.ASSETS_DIR, consts.CSL_DIR)
+        self.assertIn('csl', consts.CSL_DIR)
+
+    def test_templates_dir(self):
+        self.assertIn(consts.ASSETS_DIR, consts.TEMPLATES_DIR)
+        self.assertIn('templates', consts.TEMPLATES_DIR)
+
+    def test_static_dir(self):
+        self.assertIn(consts.ASSETS_DIR, consts.STATIC_DIR)
+        self.assertIn('static', consts.STATIC_DIR)
+
+    def test_internal_asset_dir(self):
+        self.assertIn(consts.PROJECT_DIR, consts.INTERNAL_ASSETS_DIR)
+        self.assertIn('assets', consts.INTERNAL_ASSETS_DIR)
+
+    def test_internal_static_dir(self):
+        self.assertIn(consts.PROJECT_DIR, consts.INTERNAL_STATIC_DIR)
+        self.assertIn('static', consts.INTERNAL_STATIC_DIR)
+
+    def test_internal_templates_dir(self):
+        self.assertIn(consts.PROJECT_DIR, consts.INTERNAL_TEMPLATES_DIR)
+        self.assertIn('templates', consts.INTERNAL_TEMPLATES_DIR)
+
+    def test_config_file(self):
+        self.assertIn(consts.WORKING_DIR, consts.CONFIG_FILE)
+        self.assertIn('mdp.yml', consts.CONFIG_FILE)
+
+    def test_csl_download_link(self):
+        self.assertIn('https://github.com', consts.CSL_DOWNLOAD_LINK)
+        self.assertTrue(consts.CSL_DOWNLOAD_LINK.endswith('master.zip'))
+
+    def test_csl_accessible(self):
+        response = requests.head(consts.CSL_DOWNLOAD_LINK)
+        if response.status_code == 302:
+            response = requests.head(response.headers['Location'])
+        self.assertEqual(response.status_code, 200)
+        headers = response.headers
+        self.assertEqual(headers['Content-Type'], 'application/zip')
+        self.assertEqual(headers['Content-Disposition'], 'attachment; filename=styles-master.zip')
+
+    @freeze_time('2017-01-01')
+    def test_date_format(self):
+        now = datetime.datetime.now()
+        self.assertEqual(
+            now.strftime(consts.DATE_FORMAT),
+            '01 January 2017'
+        )
+
+    @freeze_time('2017-01-01T12:34')
+    def test_time_format(self):
+        now = datetime.datetime.now()
+        self.assertEqual(
+            now.strftime(consts.TIME_FORMAT),
+            '12:34'
+        )
+
+    @freeze_time('2017-01-01T12:34')
+    def test_time_format(self):
+        now = datetime.datetime.now()
+        self.assertEqual(
+            now.strftime(consts.DATETIME_FORMAT),
+            '01 January 2017 12:34'
+        )
+
+    def test_dirs_existt(self):
+        self.assertTrue(os.path.isdir(consts.ASSETS_DIR))
+        self.assertTrue(os.path.isdir(consts.TEMPLATES_DIR))
+        self.assertTrue(os.path.isdir(consts.STATIC_DIR))
+
+
+