Work on day separators.

* Overrode ``EntryModel.{get,set}`` to return a ``Date`` object and allow you to
  set the value with either a ``Date`` object, or the JSON date string.
* Updated code to reflect the ``EntryModel.timestamp`` data change.
* Added ``daysApart`` to calculate calendar days between given ``Date``s
* Added ``getEnglishDate`` to return a date description relative to the current
  day ("Today", "Last year" for example).

www/js/ts.js

@@ -11,10 +11,40 @@ $(document).ready(function(){
      *  - id
      *  - mark
      *  - notes
-     *  - start
+     *  - timestamp
      */
     TS.EntryModel = Backbone.Model.extend({
 
+        get: function(attribute) {
+            if (attribute == "timestamp") {
+                if (!this.timestampDate) {
+                    this.timestampDate = new Date(
+                        Backbone.Model.prototype.get.call(this, attribute));
+                }
+                return this.timestampDate;
+            } else {
+                return Backbone.Model.prototype.get.call(this, attribute);
+            }
+        },
+
+        set: function(attributes, options) {
+            var attrsToSet = {}
+            _.each(attributes, function(val, key) {
+                if (key == "timestamp") {
+                    if (val instanceof Date) {
+                        this.timestampDate = val;
+                        attrsToSet.timestamp = dateToJSON(val);
+                    } else {
+                        this.timestampDate = new Date(val);
+                        attrsToSet.timestamp = dateToJSON(this.timestampDate);
+                    }
+                } else {
+                    attrsToSet[key] = val;
+                }
+            });
+
+            return Backbone.Model.prototype.set.call(this, attrsToSet, options);
+        }
     });
 
     /* Timeline model.
@@ -207,7 +237,7 @@ $(document).ready(function(){
         save: function() {
             this.model.save({
                 mark: this.$('.mark-input').val(), 
-                timestamp: this.$('.timestamp-input').val(),
+                timestamp: new Date(this.$('.timestamp-input').val()),
                 notes: this.$('.notes-input').val()});
         },
 
@@ -250,12 +280,12 @@ $(document).ready(function(){
          * @return the duration between model and nextModel, formatted for 
          *         display: `Xd Yhr Zm`. */
         formatDuration: function(model, nextModel) {
-            var d1 = new Date(model.get('timestamp'));
+            var d1 = model.get('timestamp');
             var d2, diff;
             var day, hr, min;
 
             // if no next model, assume it's an onoing task
-            if (nextModel) { d2 = new Date(nextModel.get('timestamp')); }
+            if (nextModel) { d2 = nextModel.get('timestamp'); }
             else { d2 = new Date(); }
 
             diff= d2.getTime() - d1.getTime();
@@ -345,7 +375,7 @@ $(document).ready(function(){
                 // create the mark. Immediately fetch to get server-side timestamp
                 this.collection.create({mark: entryMark,
                                         notes: '',
-                                        timestamp: getUTCTimestamp()}).fetch();
+                                        timestamp: new Date()}).fetch();
 
                 // clear the input for the next entry
                 this.$("#new-entry-input").val("");
@@ -367,11 +397,23 @@ $(document).ready(function(){
                 userExclusions.concat(timelineExclusions),
                 function(exclusion) { return new RegExp(exclusion)} );
 
+            // clear existing elements in the view container
             this.entryContainer.empty();
+
+            // last day we have printed a separator for
+            var currentDay = null;
+            var today = new Date();
+
+            // iterate through the collection and render the elements.
             for (var i = 0, len = this.collection.length; i < len; i++) {
                 var entry = this.collection.at(i);
                 var nextEntry = (i + 1 < len ? this.collection.at(i + 1) : null);
 
+                if (currentDay != entry.get('timestamp').getDate()) {
+                    currentDay = entry.get('timestamp').getDate();
+
+                }
+
                 this.renderOne(entry, nextEntry);
             }
         }
@@ -687,7 +729,7 @@ $(document).ready(function(){
             var timelineDesc = this.$("#new-timeline-desc").val();
             this.timelineCollection.create(
                 {id: timelineId, description: timelineDesc, 
-                 created: getUTCTimestamp()});
+                 created: dateToJSON(new Date())});
             this.hide();
         },
 
@@ -705,9 +747,7 @@ $(document).ready(function(){
 
 })
 
-function getUTCTimestamp() {
-    var d = new Date();
-
+function dateToJSON(d) {
     function pad(n){return n<10 ? '0'+n : n}
 
     return d.getUTCFullYear()+'-'
@@ -718,3 +758,58 @@ function getUTCTimestamp() {
         + pad(d.getUTCSeconds())+'Z';
 }
 
+function daysApart(d1, d2) {
+    var daysInMonth = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30];
+
+    days1 = (d1.getFullYear() * 365) + daysInMonth[d1.getMonth()] + d1.getDate();
+    days2 = (d2.getFullYear() * 365) + daysInMonth[d2.getMonth()] + d2.getDate();
+
+    return days1 - days2;
+}
+
+function getEnglishDate(d) {
+    if (typeof getEnglishDate.today == 'undefined') {
+        getEnglishDate.today = new Date() };
+
+    var yearDiff = today.getFullYear() - d.getFullYear();
+    var monthDiff = today.getMonth() - d.getMonth();
+    var dayDiff = today.getDate() - d.getDate();
+
+    if (yearDiff > 1) { return capitalize(toWords(yearDiff)) + " years ago."; }
+    else if (yearDiff > 0) { return "Last year"; }
+    else if (monthDiff > 1) {
+        return capitalize(toWords(monthDiff)) + "months ago."; }
+    else if (monthDiff > 0) { return "Last month."; }
+    else if (dayDiff > 0) {
+        // weeks as 7-day periods
+        var weekDiff = Math.ceil(dayDiff / 7)
+
+        // adjust for the hard boundary of the weekend
+        if (today.getDay() > d.getDay()) { weekDiff--; }
+
+        if (weekDiff > 1) {
+            return capitalize(toWords(weekDiff)) + " weeks ago."; }
+        else if (weekDiff > 0) { return "Last week."; }
+        else { return capitalize(toWords(dayDiff)) + " days ago."; }
+
+    } else if (yearDiff < 0 || monthDiff < 0 || daysDiff < 0) {
+        return "In the future."; }
+    else { return "Today."; }
+}
+
+
+function toWords(i) {
+    if (typeof toWords.words == 'undefined') {
+        toWords.words = ['zero','one','two','three','four', 'five','six',
+                          'seven','eight','nine','ten','eleven','twelve',
+                          'thirteen', 'fourteen','fifteen','sixteen',
+                          'seventeen','eighteen','nineteen' ];
+    }
+
+    if (i < 20) { return toWords.words[i]; }
+    else { return i.toString(); }
+}
+
+function capitalize(s) {
+    return s.slice(0, 1).toUpperCase() + s.slice(1);
+}