New: Series Overview sorted by Next Airing now sorts all remaining items by their Last Aired date.

src/NzbDrone.Api/Series/SeriesModule.cs

@@ -177,6 +177,7 @@ private void LinkSeriesStatistics(SeriesResource resource, SeriesStatistics seri
             resource.EpisodeCount = seriesStatistics.EpisodeCount;
             resource.EpisodeFileCount = seriesStatistics.EpisodeFileCount;
             resource.NextAiring = seriesStatistics.NextAiring;
+            resource.PreviousAiring = seriesStatistics.PreviousAiring;
         }
 
         public void Handle(EpisodeImportedEvent message)

src/NzbDrone.Api/Series/SeriesResource.cs

@@ -34,6 +34,7 @@ public Int32 SeasonCount
         public String QualityProfileName { get; set; }
         public String Overview { get; set; }
         public DateTime? NextAiring { get; set; }
+        public DateTime? PreviousAiring { get; set; }
         public String Network { get; set; }
         public String AirTime { get; set; }
         public List<MediaCover> Images { get; set; }

src/NzbDrone.Core.Test/SeriesStatsTests/SeriesStatisticsFixture.cs

@@ -39,6 +39,11 @@ private void GivenEpisodeWithFile()
             _episode.EpisodeFileId = 1;
         }
 
+        private void GivenOldEpisode()
+        {
+            _episode.AirDateUtc = DateTime.Now.AddSeconds(-10);
+        }
+
         private void GivenMonitoredEpisode()
         {
             _episode.Monitored = true;
@@ -59,6 +64,7 @@ public void should_get_stats_for_series()
 
             stats.Should().HaveCount(1);
             stats.First().NextAiring.Should().Be(_episode.AirDateUtc);
+            stats.First().PreviousAiring.Should().NotHaveValue();
         }
 
         [Test]
@@ -73,6 +79,47 @@ public void should_not_have_next_airing_for_episode_with_file()
             stats.First().NextAiring.Should().NotHaveValue();
         }
 
+        [Test]
+        public void should_have_previous_airing_for_old_episode_with_file()
+        {
+            GivenEpisodeWithFile();
+            GivenOldEpisode();
+            GivenFile();
+
+            var stats = Subject.SeriesStatistics();
+
+            stats.Should().HaveCount(1);
+            stats.First().NextAiring.Should().NotHaveValue();
+            stats.First().PreviousAiring.Should().Be(_episode.AirDateUtc);
+        }
+
+        [Test]
+        public void should_have_previous_airing_for_old_episode_without_file_monitored()
+        {
+            GivenMonitoredEpisode();
+            GivenOldEpisode();
+            GivenFile();
+
+            var stats = Subject.SeriesStatistics();
+
+            stats.Should().HaveCount(1);
+            stats.First().NextAiring.Should().NotHaveValue();
+            stats.First().PreviousAiring.Should().Be(_episode.AirDateUtc);
+        }
+
+        [Test]
+        public void should_not_have_previous_airing_for_old_episode_without_file_unmonitored()
+        {
+            GivenOldEpisode();
+            GivenFile();
+
+            var stats = Subject.SeriesStatistics();
+
+            stats.Should().HaveCount(1);
+            stats.First().NextAiring.Should().NotHaveValue();
+            stats.First().PreviousAiring.Should().NotHaveValue();
+        }
+
         [Test]
         public void should_not_include_unmonitored_episode_in_episode_count()
         {

src/NzbDrone.Core/SeriesStats/SeriesStatistics.cs

@@ -7,6 +7,7 @@ public class SeriesStatistics : ResultSet
     {
         public int SeriesId { get; set; }
         public string NextAiringString { get; set; }
+        public string PreviousAiringString { get; set; }
         public int EpisodeFileCount { get; set; }
         public int EpisodeCount { get; set; }
 
@@ -21,5 +22,17 @@ public DateTime? NextAiring
                 return nextAiring;
             }
         }
+
+        public DateTime? PreviousAiring
+        {
+            get
+            {
+                DateTime previousAiring;
+
+                if (!DateTime.TryParse(PreviousAiringString, out previousAiring)) return null;
+
+                return previousAiring;
+            }
+        }
     }
 }

src/NzbDrone.Core/SeriesStats/SeriesStatisticsRepository.cs

@@ -56,7 +56,8 @@ private string GetSelectClause()
                      SeriesId,
                      SUM(CASE WHEN (Monitored = 1 AND AirdateUtc <= @currentDate) OR EpisodeFileId > 0 THEN 1 ELSE 0 END) AS EpisodeCount,
                      SUM(CASE WHEN EpisodeFileId > 0 THEN 1 ELSE 0 END) AS EpisodeFileCount,
-                     MIN(CASE WHEN AirDateUtc < @currentDate OR EpisodeFileId > 0 OR Monitored = 0 THEN NULL ELSE AirDateUtc END) AS NextAiringString
+                     MIN(CASE WHEN AirDateUtc < @currentDate OR EpisodeFileId > 0 OR Monitored = 0 THEN NULL ELSE AirDateUtc END) AS NextAiringString,
+                     MAX(CASE WHEN AirDateUtc >= @currentDate OR EpisodeFileId = 0 AND Monitored = 0 THEN NULL ELSE AirDateUtc END) AS PreviousAiringString
                      FROM Episodes";
         }
 

src/UI/Series/SeriesCollection.js

@@ -59,12 +59,18 @@ define(
             //Sorters
             nextAiring: function (model, attr) {
                 var nextAiring = model.get(attr);
-
-                if (!nextAiring) {
-                    return Number.MAX_VALUE;
+                
+                if (nextAiring) {
+                    return Moment(nextAiring).unix();
+                }
+                
+                var previousAiring = model.get(attr.replace('nextAiring', 'previousAiring'));
+                
+                if (previousAiring) {
+                    return 10000000000 - Moment(previousAiring).unix();
                 }
 
-                return Moment(nextAiring).unix();
+                return Number.MAX_VALUE;
             }
         });