Some code cleanup. Allow NextUpDateCutoff to be null

Emby.Server.Implementations/TV/TVSeriesManager.cs

@@ -156,7 +156,7 @@ namespace Emby.Server.Implementations.TV
                         return i.Item1 != DateTime.MinValue;
                     }
 
-                    if (alwaysEnableFirstEpisode || (i.Item1 != DateTime.MinValue && i.Item1.Date > request.NextUpDateCutoff))
+                    if (alwaysEnableFirstEpisode || (i.Item1 != DateTime.MinValue && (request.NextUpDateCutoff is null ||  i.Item1.Date > request.NextUpDateCutoff)))
                     {
                         anyFound = true;
                         return true;

Jellyfin.Api/Controllers/TvShowsController.cs

@@ -82,7 +82,7 @@ namespace Jellyfin.Api.Controllers
             [FromQuery] int? imageTypeLimit,
             [FromQuery, ModelBinder(typeof(CommaDelimitedArrayModelBinder))] ImageType[] enableImageTypes,
             [FromQuery] bool? enableUserData,
-            [FromQuery] DateTime nextUpDateCutoff,
+            [FromQuery] DateTime? nextUpDateCutoff,
             [FromQuery] bool enableTotalRecordCount = true,
             [FromQuery] bool disableFirstEpisode = false)
         {

MediaBrowser.Model/Querying/NextUpQuery.cs

@@ -13,7 +13,7 @@ namespace MediaBrowser.Model.Querying
             EnableImageTypes = Array.Empty<ImageType>();
             EnableTotalRecordCount = true;
             DisableFirstEpisode = false;
-            NextUpDateCutoff = new DateTime(0001, 01, 01);
+            NextUpDateCutoff = null;
         }
 
         /// <summary>
@@ -80,6 +80,6 @@ namespace MediaBrowser.Model.Querying
         /// <summary>
         /// Gets or sets a value indicating the oldest date for a show to appear in Next Up.
         /// </summary>
-        public DateTime NextUpDateCutoff { get; set; }
+        public DateTime? NextUpDateCutoff { get; set; }
     }
 }