diff --git a/js/common/util/compute_domain.js b/js/common/util/compute_domain.js
new file mode 100644
index 0000000000..58faa51be7
--- /dev/null
+++ b/js/common/util/compute_domain.js
@@ -0,0 +1,7 @@
+export default function computeDomain(stateObj) {
+  if (!stateObj._domain) {
+    stateObj._domain = stateObj.entity_id.substr(0, stateObj.entity_id.indexOf('.'));
+  }
+
+  return stateObj._domain;
+}
diff --git a/js/common/util/compute_state_display.js b/js/common/util/compute_state_display.js
new file mode 100644
index 0000000000..a43175de4a
--- /dev/null
+++ b/js/common/util/compute_state_display.js
@@ -0,0 +1,59 @@
+import computeDomain from './compute_domain';
+import formatDateTime from './format_date_time';
+import formatDate from './format_date';
+import formatTime from './format_time';
+
+export default function computeStateDisplay(haLocalize, stateObj, language) {
+  if (!stateObj._stateDisplay) {
+    const domain = computeDomain(stateObj);
+    if (domain === 'binary_sensor') {
+      // Try device class translation, then default binary sensor translation
+      if (stateObj.attributes.device_class) {
+        stateObj._stateDisplay =
+          haLocalize(`state.${domain}.${stateObj.attributes.device_class}`, stateObj.state);
+      }
+      if (!stateObj._stateDisplay) {
+        stateObj._stateDisplay = haLocalize(`state.${domain}.default`, stateObj.state);
+      }
+    } else if (stateObj.attributes.unit_of_measurement) {
+      stateObj._stateDisplay = stateObj.state + ' ' + stateObj.attributes.unit_of_measurement;
+    } else if (domain === 'input_datetime') {
+      let date;
+      if (!stateObj.attributes.has_time) {
+        date = new Date(
+          stateObj.attributes.year,
+          stateObj.attributes.month - 1,
+          stateObj.attributes.day
+        );
+        stateObj._stateDisplay = formatDate(date, language);
+      } else if (!stateObj.attributes.has_date) {
+        date = new Date(
+          1970, 0, 1,
+          stateObj.attributes.hour,
+          stateObj.attributes.minute
+        );
+        stateObj._stateDisplay = formatTime(date, language);
+      } else {
+        date = new Date(
+          stateObj.attributes.year, stateObj.attributes.month - 1,
+          stateObj.attributes.day, stateObj.attributes.hour,
+          stateObj.attributes.minute
+        );
+        stateObj._stateDisplay = formatDateTime(date, language);
+      }
+    } else if (domain === 'zwave') {
+      if (['initializing', 'dead'].includes(stateObj.state)) {
+        stateObj._stateDisplay = haLocalize('state.zwave.query_stage', stateObj.state, 'query_stage', stateObj.attributes.query_stage);
+      } else {
+        stateObj._stateDisplay = haLocalize('state.zwave.default', stateObj.state);
+      }
+    } else {
+      stateObj._stateDisplay = haLocalize(`state.${domain}`, stateObj.state);
+    }
+    // Fall back to default or raw state if nothing else matches.
+    stateObj._stateDisplay = stateObj._stateDisplay
+      || haLocalize('state.default', stateObj.state) || stateObj.state;
+  }
+
+  return stateObj._stateDisplay;
+}
diff --git a/js/common/util/format_date.js b/js/common/util/format_date.js
new file mode 100644
index 0000000000..006e736f88
--- /dev/null
+++ b/js/common/util/format_date.js
@@ -0,0 +1,19 @@
+// Check for support of native locale string options
+function toLocaleDateStringSupportsOptions() {
+  try {
+    new Date().toLocaleDateString('i');
+  } catch (e) {
+    return e.name === 'RangeError';
+  }
+  return false;
+}
+
+export default (toLocaleDateStringSupportsOptions() ?
+  function (dateObj, locales) {
+    return dateObj.toLocaleDateString(
+      locales,
+      { year: 'numeric', month: 'long', day: 'numeric' },
+    );
+  } : function (dateObj, locales) { // eslint-disable-line no-unused-vars
+    return window.fecha.format(dateObj, 'mediumDate');
+  });
diff --git a/js/common/util/format_date_time.js b/js/common/util/format_date_time.js
new file mode 100644
index 0000000000..f695511b86
--- /dev/null
+++ b/js/common/util/format_date_time.js
@@ -0,0 +1,22 @@
+// Check for support of native locale string options
+function toLocaleStringSupportsOptions() {
+  try {
+    new Date().toLocaleString('i');
+  } catch (e) {
+    return e.name === 'RangeError';
+  }
+  return false;
+}
+
+export default (toLocaleStringSupportsOptions() ?
+  function (dateObj, locales) {
+    return dateObj.toLocaleString(locales, {
+      year: 'numeric',
+      month: 'long',
+      day: 'numeric',
+      hour: 'numeric',
+      minute: '2-digit',
+    });
+  } : function (dateObj, locales) { // eslint-disable-line no-unused-vars
+    return window.fecha.format(dateObj, 'haDateTime');
+  });
diff --git a/js/common/util/format_time.js b/js/common/util/format_time.js
new file mode 100644
index 0000000000..5ff05a67da
--- /dev/null
+++ b/js/common/util/format_time.js
@@ -0,0 +1,19 @@
+// Check for support of native locale string options
+function toLocaleTimeStringSupportsOptions() {
+  try {
+    new Date().toLocaleTimeString('i');
+  } catch (e) {
+    return e.name === 'RangeError';
+  }
+  return false;
+}
+
+export default (toLocaleTimeStringSupportsOptions() ?
+  function (dateObj, locales) {
+    return dateObj.toLocaleTimeString(
+      locales,
+      { hour: 'numeric', minute: '2-digit' }
+    );
+  } : function (dateObj, locales) { // eslint-disable-line no-unused-vars
+    return window.fecha.format(dateObj, 'shortTime');
+  });
diff --git a/js/util.js b/js/util.js
index 621f7e0019..eb97c013ac 100644
--- a/js/util.js
+++ b/js/util.js
@@ -7,7 +7,22 @@
  */
 
 import attributeClassNames from './common/util/attribute_class_names';
+import computeDomain from './common/util/compute_domain';
+import computeStateDisplay from './common/util/compute_state_display';
+import formatDate from './common/util/format_date';
+import formatDateTime from './common/util/format_date_time';
+import formatTime from './common/util/format_time';
 
 window.hassUtil = window.hassUtil || {};
 
+const language = navigator.languages ?
+  navigator.languages[0] : navigator.language || navigator.userLanguage;
+
+window.fecha.masks.haDateTime = window.fecha.masks.shortTime + ' ' + window.fecha.masks.mediumDate;
+
 window.hassUtil.attributeClassNames = attributeClassNames;
+window.hassUtil.computeDomain = computeDomain;
+window.hassUtil.computeStateDisplay = computeStateDisplay;
+window.hassUtil.formatDate = dateObj => formatDate(dateObj, language);
+window.hassUtil.formatDateTime = dateObj => formatDateTime(dateObj, language);
+window.hassUtil.formatTime = dateObj => formatTime(dateObj, language);
diff --git a/src/components/ha-cards.html b/src/components/ha-cards.html
index e4d35670ea..f6e81a4ff5 100644
--- a/src/components/ha-cards.html
+++ b/src/components/ha-cards.html
@@ -7,6 +7,8 @@
 <link rel="import" href="../cards/ha-badges-card.html">
 <link rel="import" href="../cards/ha-card-chooser.html">
 
+<link rel="import" href="../util/hass-util.html">
+
 <dom-module id="ha-cards">
   <template>
     <style is="custom-style" include="iron-flex iron-flex-factors"></style>
diff --git a/src/home-assistant.html b/src/home-assistant.html
index 56c549a09f..587808d958 100644
--- a/src/home-assistant.html
+++ b/src/home-assistant.html
@@ -2,7 +2,6 @@
 <script>
   Polymer.setPassiveTouchGestures(true);
 </script>
-<link rel='import' href='../bower_components/app-localize-behavior/app-localize-behavior.html'>
 <link rel='import' href='./util/roboto.html'>
 <link rel='import' href='../bower_components/paper-styles/typography.html'>
 <link rel='import' href='../bower_components/iron-flex-layout/iron-flex-layout-classes.html'>
diff --git a/src/state-summary/state-card-display.html b/src/state-summary/state-card-display.html
index dbb0a061e7..411158c411 100644
--- a/src/state-summary/state-card-display.html
+++ b/src/state-summary/state-card-display.html
@@ -3,6 +3,8 @@
 <link rel="import" href="../../bower_components/iron-flex-layout/iron-flex-layout-classes.html">
 
 <link rel="import" href="../components/entity/state-info.html">
+<link rel="import" href="../util/hass-mixins.html">
+<link rel="import" href="../util/hass-util.html">
 
 <dom-module id="state-card-display">
   <template>
@@ -20,7 +22,7 @@
 
     <div class='horizontal justified layout'>
       <state-info state-obj="[[stateObj]]" in-dialog='[[inDialog]]'></state-info>
-      <div class='state'>[[computeStateDisplay(haLocalize, stateObj)]]</div>
+      <div class='state'>[[computeStateDisplay(haLocalize, stateObj, language)]]</div>
     </div>
   </template>
 </dom-module>
@@ -40,55 +42,8 @@ class StateCardDisplay extends window.hassMixins.LocalizeMixin(Polymer.Element)
     };
   }
 
-  computeStateDisplay(haLocalize, stateObj) {
-    if (!stateObj._stateDisplay) {
-      const domain = window.hassUtil.computeDomain(stateObj);
-      if (domain === 'binary_sensor') {
-        // Try device class translation, then default binary sensor translation
-        stateObj._stateDisplay =
-          haLocalize(`state.${domain}.${stateObj.attributes.device_class}`, stateObj.state)
-          || haLocalize(`state.${domain}.default`, stateObj.state);
-      } else if (stateObj.attributes.unit_of_measurement) {
-        stateObj._stateDisplay = stateObj.state + ' ' + stateObj.attributes.unit_of_measurement;
-      } else if (domain === 'input_datetime') {
-        let date;
-        if (!stateObj.attributes.has_time) {
-          date = new Date(
-            stateObj.attributes.year,
-            stateObj.attributes.month - 1,
-            stateObj.attributes.day
-          );
-          stateObj._stateDisplay = window.hassUtil.formatDate(date);
-        } else if (!stateObj.attributes.has_date) {
-          date = new Date(
-            1970, 0, 1,
-            stateObj.attributes.hour,
-            stateObj.attributes.minute
-          );
-          stateObj._stateDisplay = window.hassUtil.formatTime(date);
-        } else {
-          date = new Date(
-            stateObj.attributes.year, stateObj.attributes.month - 1,
-            stateObj.attributes.day, stateObj.attributes.hour,
-            stateObj.attributes.minute
-          );
-          stateObj._stateDisplay = window.hassUtil.formatDateTime(date);
-        }
-      } else if (domain === 'zwave') {
-        if (['initializing', 'dead'].includes(stateObj.state)) {
-          stateObj._stateDisplay = haLocalize('state.zwave.query_stage', stateObj.state, 'query_stage', stateObj.attributes.query_stage);
-        } else {
-          stateObj._stateDisplay = haLocalize('state.zwave.default', stateObj.state);
-        }
-      } else {
-        stateObj._stateDisplay = haLocalize(`state.${domain}`, stateObj.state);
-      }
-      // Fall back to default or raw state if nothing else matches.
-      stateObj._stateDisplay = stateObj._stateDisplay
-        || haLocalize('state.default', stateObj.state) || stateObj.state;
-    }
-
-    return stateObj._stateDisplay;
+  computeStateDisplay(haLocalize, stateObj, language) {
+    return window.hassUtil.computeStateDisplay(haLocalize, stateObj, language);
   }
 }
 customElements.define(StateCardDisplay.is, StateCardDisplay);
diff --git a/src/util/hass-mixins.html b/src/util/hass-mixins.html
index 219db5fc35..cf200353f5 100644
--- a/src/util/hass-mixins.html
+++ b/src/util/hass-mixins.html
@@ -1,3 +1,5 @@
+<link rel='import' href='../../bower_components/app-localize-behavior/app-localize-behavior.html'>
+
 <script>
 
 // Polymer legacy event helpers used courtesy of the Polymer project.
diff --git a/src/util/hass-util.html b/src/util/hass-util.html
index d26e1b2b73..5b5e78b35a 100644
--- a/src/util/hass-util.html
+++ b/src/util/hass-util.html
@@ -36,9 +36,6 @@ window.hassUtil.HIDE_MORE_INFO = [
   'input_select', 'scene', 'input_number', 'input_text'
 ];
 
-window.hassUtil.LANGUAGE = navigator.languages ?
-  navigator.languages[0] : navigator.language || navigator.userLanguage;
-
 // Expects featureClassNames to be an object mapping feature-bit -> className
 window.hassUtil.featureClassNames = function (stateObj, featureClassNames) {
   if (!stateObj || !stateObj.attributes.supported_features) return '';
@@ -107,77 +104,6 @@ window.hassUtil.dynamicContentUpdater = function (root, newElementTag, attribute
   }
 };
 
-// Check for support of native locale string options
-function toLocaleStringSupportsOptions() {
-  try {
-    new Date().toLocaleString('i');
-  } catch (e) {
-    return e.name === 'RangeError';
-  }
-  return false;
-}
-function toLocaleDateStringSupportsOptions() {
-  try {
-    new Date().toLocaleDateString('i');
-  } catch (e) {
-    return e.name === 'RangeError';
-  }
-  return false;
-}
-function toLocaleTimeStringSupportsOptions() {
-  try {
-    new Date().toLocaleTimeString('i');
-  } catch (e) {
-    return e.name === 'RangeError';
-  }
-  return false;
-}
-
-window.fecha.masks.haDateTime = (window.fecha.masks.shortTime + ' ' +
-                                 window.fecha.masks.mediumDate);
-
-if (toLocaleStringSupportsOptions()) {
-  window.hassUtil.formatDateTime = function (dateObj) {
-    return dateObj.toLocaleString(window.hassUtil.LANGUAGE, {
-      year: 'numeric',
-      month: 'long',
-      day: 'numeric',
-      hour: 'numeric',
-      minute: '2-digit',
-    });
-  };
-} else {
-  window.hassUtil.formatDateTime = function (dateObj) {
-    return window.fecha.format(dateObj, 'haDateTime');
-  };
-}
-
-if (toLocaleDateStringSupportsOptions()) {
-  window.hassUtil.formatDate = function (dateObj) {
-    return dateObj.toLocaleDateString(
-      window.hassUtil.LANGUAGE,
-      { year: 'numeric', month: 'long', day: 'numeric' }
-    );
-  };
-} else {
-  window.hassUtil.formatDate = function (dateObj) {
-    return window.fecha.format(dateObj, 'mediumDate');
-  };
-}
-
-if (toLocaleTimeStringSupportsOptions()) {
-  window.hassUtil.formatTime = function (dateObj) {
-    return dateObj.toLocaleTimeString(
-      window.hassUtil.LANGUAGE,
-      { hour: 'numeric', minute: '2-digit' }
-    );
-  };
-} else {
-  window.hassUtil.formatTime = function (dateObj) {
-    return window.fecha.format(dateObj, 'shortTime');
-  };
-}
-
 window.hassUtil.relativeTime = function (dateObj) {
   var delta = Math.abs(new Date() - dateObj) / 1000;
   var format = new Date() > dateObj ? '%s ago' : 'in %s';
@@ -437,14 +363,6 @@ window.hassUtil.stateIcon = function (state) {
   return window.hassUtil.domainIcon(domain, state.state);
 };
 
-window.hassUtil.computeDomain = function (stateObj) {
-  if (!stateObj._domain) {
-    stateObj._domain = window.HAWS.extractDomain(stateObj.entity_id);
-  }
-
-  return stateObj._domain;
-};
-
 window.hassUtil.computeObjectId = function (stateObj) {
   if (!stateObj._object_id) {
     stateObj._object_id = window.HAWS.extractObjectId(stateObj.entity_id);
diff --git a/test-mocha/common/util/attribute_class_names_test.js b/test-mocha/common/util/attribute_class_names_test.js
index fdd31c5983..3088cd12c8 100644
--- a/test-mocha/common/util/attribute_class_names_test.js
+++ b/test-mocha/common/util/attribute_class_names_test.js
@@ -5,14 +5,14 @@ const assert = require('assert');
 describe('attributeClassNames', function() {
   const attrs = ['mock_attr1', 'mock_attr2'];
 
-  it('null state', function() {
+  it('Skips null states', function() {
     const stateObj = null;
     assert.strictEqual(
       attributeClassNames(stateObj, attrs),
       '');
   });
 
-  it('matches no attrbutes', function() {
+  it('Matches no attrbutes', function() {
     const stateObj = {
       attributes: {
         other_attr_1: 1,
@@ -24,7 +24,7 @@ describe('attributeClassNames', function() {
       '');
   });
 
-  it('matches one attrbute', function() {
+  it('Matches one attrbute', function() {
     const stateObj = {
       attributes: {
         other_attr_1: 1,
@@ -37,7 +37,7 @@ describe('attributeClassNames', function() {
       'has-mock_attr1');
   });
 
-  it('matches two attrbutes', function() {
+  it('Matches two attrbutes', function() {
     const stateObj = {
       attributes: {
         other_attr_1: 1,
diff --git a/test-mocha/common/util/compute_domain.js b/test-mocha/common/util/compute_domain.js
new file mode 100644
index 0000000000..e26811b242
--- /dev/null
+++ b/test-mocha/common/util/compute_domain.js
@@ -0,0 +1,12 @@
+import computeDomain from '../../../js/common/util/compute_domain';
+
+const assert = require('assert');
+
+describe('computeDomain', function() {
+  it('Detects sensor domain', function() {
+    const stateObj = {
+      entity_id: 'sensor.test',
+    };
+    assert.strictEqual(computeDomain(stateObj), 'sensor');
+  });
+});
diff --git a/test-mocha/common/util/compute_state_display.js b/test-mocha/common/util/compute_state_display.js
new file mode 100644
index 0000000000..a49a0e3848
--- /dev/null
+++ b/test-mocha/common/util/compute_state_display.js
@@ -0,0 +1,184 @@
+import computeStateDisplay from '../../../js/common/util/compute_state_display';
+
+const assert = require('assert');
+
+describe('computeStateDisplay', function() {
+  const haLocalize = function(namespace, message, ...args) {
+    // Mock Localize function for testing
+    return namespace + '.' + message + (args.length ? ': ' + args.join(',') : '');
+  };
+
+  it('Localizes binary sensor defaults', function() {
+    const stateObj = {
+      entity_id: 'binary_sensor.test',
+      state: 'off',
+      attributes: {
+      },
+    };
+    assert.strictEqual(computeStateDisplay(haLocalize, stateObj, 'en'), 'state.binary_sensor.default.off');
+  });
+
+  it('Localizes binary sensor device class', function() {
+    const stateObj = {
+      entity_id: 'binary_sensor.test',
+      state: 'off',
+      attributes: {
+        device_class: 'moisture',
+      },
+    };
+    assert.strictEqual(computeStateDisplay(haLocalize, stateObj, 'en'), 'state.binary_sensor.moisture.off');
+  });
+
+  it('Localizes binary sensor invalid device class', function() {
+    const altHaLocalize = function(namespace, message, ...args) {
+      if (namespace === 'state.binary_sensor.invalid_device_class') return null;
+      return haLocalize(namespace, message, ...args);
+    };
+    const stateObj = {
+      entity_id: 'binary_sensor.test',
+      state: 'off',
+      attributes: {
+        device_class: 'invalid_device_class',
+      },
+    };
+    assert.strictEqual(computeStateDisplay(altHaLocalize, stateObj, 'en'), 'state.binary_sensor.default.off');
+  });
+
+  it('Localizes sensor value with units', function() {
+    const stateObj = {
+      entity_id: 'sensor.test',
+      state: '123',
+      attributes: {
+        unit_of_measurement: 'm',
+      },
+    };
+    assert.strictEqual(computeStateDisplay(haLocalize, stateObj, 'en'), '123 m');
+  });
+
+  it('Localizes input_datetime with full date time', function() {
+    const stateObj = {
+      entity_id: 'input_datetime.test',
+      state: '123',
+      attributes: {
+        has_date: true,
+        has_time: true,
+        year: 2017,
+        month: 11,
+        day: 18,
+        hour: 11,
+        minute: 12,
+        second: 13,
+      },
+    };
+    assert.strictEqual(computeStateDisplay(haLocalize, stateObj, 'en'), 'November 18, 2017, 11:12 AM');
+  });
+
+  it('Localizes input_datetime with date', function() {
+    const stateObj = {
+      entity_id: 'input_datetime.test',
+      state: '123',
+      attributes: {
+        has_date: true,
+        has_time: false,
+        year: 2017,
+        month: 11,
+        day: 18,
+        hour: 11,
+        minute: 12,
+        second: 13,
+      },
+    };
+    assert.strictEqual(computeStateDisplay(haLocalize, stateObj, 'en'), 'November 18, 2017');
+  });
+
+  it('Localizes input_datetime with time', function() {
+    const stateObj = {
+      entity_id: 'input_datetime.test',
+      state: '123',
+      attributes: {
+        has_date: false,
+        has_time: true,
+        year: 2017,
+        month: 11,
+        day: 18,
+        hour: 11,
+        minute: 12,
+        second: 13,
+      },
+    };
+    assert.strictEqual(computeStateDisplay(haLocalize, stateObj, 'en'), '11:12 AM');
+  });
+
+  it('Localizes zwave ready', function() {
+    const stateObj = {
+      entity_id: 'zwave.test',
+      state: 'ready',
+      attributes: {
+        query_stage: 'Complete',
+      },
+    };
+    assert.strictEqual(computeStateDisplay(haLocalize, stateObj, 'en'), 'state.zwave.default.ready');
+  });
+
+  it('Localizes zwave initializing', function() {
+    const stateObj = {
+      entity_id: 'zwave.test',
+      state: 'initializing',
+      attributes: {
+        query_stage: 'Probe',
+      },
+    };
+    assert.strictEqual(computeStateDisplay(haLocalize, stateObj, 'en'), 'state.zwave.query_stage.initializing: query_stage,Probe');
+  });
+
+  it('Localizes cover open', function() {
+    const stateObj = {
+      entity_id: 'cover.test',
+      state: 'open',
+      attributes: {
+      },
+    };
+    assert.strictEqual(computeStateDisplay(haLocalize, stateObj, 'en'), 'state.cover.open');
+  });
+
+  it('Localizes unavailable', function() {
+    const altHaLocalize = function(namespace, message, ...args) {
+      if (namespace === 'state.sensor') return null;
+      return haLocalize(namespace, message, ...args);
+    };
+    const stateObj = {
+      entity_id: 'sensor.test',
+      state: 'unavailable',
+      attributes: {
+      },
+    };
+    assert.strictEqual(computeStateDisplay(altHaLocalize, stateObj, 'en'), 'state.default.unavailable');
+  });
+
+  it('Localizes custom state', function() {
+    const altHaLocalize = function(namespace, message, ...args) {
+      // No matches can be found
+      return null;
+    };
+    const stateObj = {
+      entity_id: 'sensor.test',
+      state: 'My Custom State',
+      attributes: {
+      },
+    };
+    assert.strictEqual(computeStateDisplay(altHaLocalize, stateObj, 'en'), 'My Custom State');
+  });
+
+  it('Only calculates state display once per immutable state object', function() {
+    const stateObj = {
+      entity_id: 'cover.test',
+      state: 'open',
+      attributes: {
+      },
+    };
+    assert.strictEqual(computeStateDisplay(haLocalize, stateObj, 'en'), 'state.cover.open');
+
+    stateObj.state = 'closing';
+    assert.strictEqual(computeStateDisplay(haLocalize, stateObj, 'en'), 'state.cover.open');
+  });
+});
diff --git a/test-mocha/common/util/format_date.js b/test-mocha/common/util/format_date.js
new file mode 100644
index 0000000000..d681a58b37
--- /dev/null
+++ b/test-mocha/common/util/format_date.js
@@ -0,0 +1,20 @@
+import formatDate from '../../../js/common/util/format_date';
+
+const assert = require('assert');
+
+describe('formatDate', function() {
+  const dateObj = new Date(
+    2017, 10, 18,
+    11, 12, 13, 1400,
+  );
+
+  it('Formats English dates', function() {
+    assert.strictEqual(formatDate(dateObj, 'en'), 'November 18, 2017');
+  });
+
+  // Node only contains intl support for english formats. This test at least ensures
+  // the fallback to a different locale
+  it('Formats other dates', function() {
+    assert.strictEqual(formatDate(dateObj, 'fr'), '2017 M11 18');
+  });
+});
diff --git a/test-mocha/common/util/format_date_time.js b/test-mocha/common/util/format_date_time.js
new file mode 100644
index 0000000000..4b22a54ad1
--- /dev/null
+++ b/test-mocha/common/util/format_date_time.js
@@ -0,0 +1,20 @@
+import formatDateTime from '../../../js/common/util/format_date_time';
+
+const assert = require('assert');
+
+describe('formatDateTime', function() {
+  const dateObj = new Date(
+    2017, 10, 18,
+    11, 12, 13, 1400,
+  );
+
+  it('Formats English date times', function() {
+    assert.strictEqual(formatDateTime(dateObj, 'en'), 'November 18, 2017, 11:12 AM');
+  });
+
+  // Node only contains intl support for english formats. This test at least ensures
+  // the fallback to a different locale
+  it('Formats other date times', function() {
+    assert.strictEqual(formatDateTime(dateObj, 'fr'), '2017 M11 18 11:12');
+  });
+});
diff --git a/test-mocha/common/util/format_time.js b/test-mocha/common/util/format_time.js
new file mode 100644
index 0000000000..66d4c9105b
--- /dev/null
+++ b/test-mocha/common/util/format_time.js
@@ -0,0 +1,20 @@
+import formatTime from '../../../js/common/util/format_time';
+
+const assert = require('assert');
+
+describe('formatTime', function() {
+  const dateObj = new Date(
+    2017, 10, 18,
+    11, 12, 13, 1400,
+  );
+
+  it('Formats English times', function() {
+    assert.strictEqual(formatTime(dateObj, 'en'), '11:12 AM');
+  });
+
+  // Node only contains intl support for english formats. This test at least ensures
+  // the fallback to a different locale
+  it('Formats other times', function() {
+    assert.strictEqual(formatTime(dateObj, 'fr'), '11:12');
+  });
+});
diff --git a/test/index.html b/test/index.html
index 6e968fff25..54b30776b6 100644
--- a/test/index.html
+++ b/test/index.html
@@ -11,6 +11,8 @@
     WCT.loadSuites([
       'state-info-test.html?dom=shadow',
       'state-info-test.html?dom=shady',
+      'state-card-display-test.html?dom=shadow',
+      'state-card-display-test.html?dom=shady',
     ]);
   </script>
 </body></html>
diff --git a/test/state-card-display-test.html b/test/state-card-display-test.html
new file mode 100644
index 0000000000..8b7099905b
--- /dev/null
+++ b/test/state-card-display-test.html
@@ -0,0 +1,64 @@
+<!doctype html>
+<html>
+<head>
+  <script src="../../webcomponentsjs/webcomponents-lite.js"></script>
+  <script src="../../web-component-tester/browser.js"></script>
+
+  <!--
+    Temporarily load core.js here so window.HAWS is available. We can remove
+    this once hass-util includes the helper function directly.
+  -->
+  <script src="../build/core.js"></script>
+  <link rel="import" href="../src/state-summary/state-card-display.html">
+</head>
+<body>
+  <test-fixture id="stateCardDisplay">
+    <template>
+      <div />
+    </template>
+  </test-fixture>
+
+  <script>
+    function lightOrShadow(elem, selector) {
+      return elem.shadowRoot ?
+          elem.shadowRoot.querySelector(selector) :
+          elem.querySelector(selector);
+    }
+
+    suite('state-card-display', function() {
+      let wrapper;
+      let card;
+
+      setup(function() {
+        wrapper = fixture('stateCardDisplay');
+        card = new StateCardDisplay();
+        card.stateObj = {
+          entity_id: 'binary_sensor.demo',
+          state: 'off',
+          attributes: {
+            device_class: 'moisture',
+          },
+        };
+        card.hass = {
+          language: 'en',
+          resources: {
+            'en': {
+              'state.binary_sensor.moisture.off': 'Mock Off Text',
+            },
+          },
+        };
+        wrapper.appendChild(card);
+      });
+
+      test('state display text', function(done) {
+        flush(function() {
+          const stateDiv = lightOrShadow(card, '.state');
+          assert.isOk(stateDiv);
+          assert.deepEqual(stateDiv.innerText, 'Mock Off Text');
+          done();
+        });
+      });
+    });
+  </script>
+</body>
+</html>
diff --git a/test/state-info-test.html b/test/state-info-test.html
index d24c8ea47e..7316a5606f 100644
--- a/test/state-info-test.html
+++ b/test/state-info-test.html
@@ -29,10 +29,6 @@
 
       setup(function() {
         si = fixture('stateInfo');
-        window.HAWS = {};
-        window.HAWS.extractDomain = function (entityId) {
-          return entityId.substr(0, entityId.indexOf('.'));
-        };
       });
       
       test('default values', function() {