diff --git a/nc_time_axis/__init__.py b/nc_time_axis/__init__.py
index 3b42a96..4ea7850 100644
--- a/nc_time_axis/__init__.py
+++ b/nc_time_axis/__init__.py
@@ -97,7 +97,7 @@ def __init__(self, max_n_ticks, calendar, date_unit, min_n_ticks=3):
         self.min_n_ticks = min_n_ticks
         self._max_n_locator = mticker.MaxNLocator(max_n_ticks, integer=True)
         self._max_n_locator_days = mticker.MaxNLocator(
-            max_n_ticks, integer=True, steps=[1, 2, 4, 7, 14])
+            max_n_ticks, integer=True, steps=[1, 2, 4, 7, 10])
         self.calendar = calendar
         self.date_unit = date_unit
         if not self.date_unit.lower().startswith('days since'):
diff --git a/nc_time_axis/tests/unit/test_NetCDFTimeConverter.py b/nc_time_axis/tests/unit/test_NetCDFTimeConverter.py
index dca5ca1..da6634c 100644
--- a/nc_time_axis/tests/unit/test_NetCDFTimeConverter.py
+++ b/nc_time_axis/tests/unit/test_NetCDFTimeConverter.py
@@ -2,6 +2,7 @@
 
 from __future__ import (absolute_import, division, print_function)
 from six.moves import (filter, input, map, range, zip)  # noqa
+from six import assertRaisesRegex
 
 import unittest
 
@@ -56,7 +57,7 @@ def test_nonequal_calendars(self):
         unit = 'days since 2000-01-01'
         val = [CalendarDateTime(cftime.datetime(2014, 8, 12), calendar_1),
                CalendarDateTime(cftime.datetime(2014, 8, 13), calendar_2)]
-        with self.assertRaisesRegexp(ValueError, 'not all equal'):
+        with assertRaisesRegex(self, ValueError, 'not all equal'):
             NetCDFTimeConverter().default_units(val, None)
 
 
@@ -98,14 +99,14 @@ def test_non_cftime_datetime(self):
         val = CalendarDateTime(4, '360_day')
         msg = 'The datetime attribute of the CalendarDateTime object must ' \
               'be of type `cftime.datetime`.'
-        with self.assertRaisesRegexp(ValueError, msg):
+        with assertRaisesRegex(self, ValueError, msg):
             result = NetCDFTimeConverter().convert(val, None, None)
 
     def test_non_CalendarDateTime(self):
         val = cftime.datetime(1988, 5, 6)
         msg = 'The values must be numbers or instances of ' \
               '"nc_time_axis.CalendarDateTime".'
-        with self.assertRaisesRegexp(ValueError, msg):
+        with assertRaisesRegex(self, ValueError, msg):
             result = NetCDFTimeConverter().convert(val, None, None)
 
 
diff --git a/nc_time_axis/tests/unit/test_NetCDFTimeDateLocator.py b/nc_time_axis/tests/unit/test_NetCDFTimeDateLocator.py
index 7e233b7..48ba8bd 100644
--- a/nc_time_axis/tests/unit/test_NetCDFTimeDateLocator.py
+++ b/nc_time_axis/tests/unit/test_NetCDFTimeDateLocator.py
@@ -5,6 +5,7 @@
 
 import unittest
 
+import matplotlib.style
 import matplotlib.dates as mdates
 import cftime
 import numpy as np
@@ -12,6 +13,9 @@
 from nc_time_axis import NetCDFTimeDateLocator
 
 
+matplotlib.style.use('classic')
+
+
 class Test_compute_resolution(unittest.TestCase):
     def setUp(self):
         self.date_unit = 'days since 2004-01-01 00:00'
@@ -108,7 +112,7 @@ def test_monthly(self):
 
     def test_yearly(self):
         np.testing.assert_array_equal(
-            self.check(5, 0, 5*365), [31., 638., 1246., 1856.])
+            self.check(5, 0, 5*365), [31., 485., 942., 1399., 1856.])
 
 
 if __name__ == "__main__":
diff --git a/setup.py b/setup.py
index f0007dd..3ac3be7 100644
--- a/setup.py
+++ b/setup.py
@@ -20,8 +20,8 @@
     author='Laura Dreyer, Philip Elson',
     url='https://github.com/scitools/nc-time-axis',
     packages=packages,
-    install_requires = ['matplotlib==1.*',
-                        'cftime',
+    install_requires = ['cftime',
+                        'matplotlib',
                         'numpy',
                         'six'],
     tests_require = ['mock', 'pep8'],