diff --git a/assets/schema/ensemble_schema.json b/assets/schema/ensemble_schema.json
index 6499aea97..f0aa4c47c 100644
--- a/assets/schema/ensemble_schema.json
+++ b/assets/schema/ensemble_schema.json
@@ -5268,6 +5268,9 @@
                   "type": "boolean",
                   "description": "Set visibility of calendar header. Default true."
                 },
+                "header": {
+                  "$ref": "#/$defs/Widget"
+                },
                 "rowSpans": {
                   "type": "array",
                   "items": {
@@ -5288,10 +5291,16 @@
                             "$ref": "#/$defs/Widget"
                           }
                         },
-                        "required": ["start", "end", "widget"]
+                        "required": [
+                          "start",
+                          "end",
+                          "widget"
+                        ]
                       }
                     },
-                    "required": ["span"]
+                    "required": [
+                      "span"
+                    ]
                   }
                 },
                 "headerTextStyle": {
diff --git a/lib/action/invoke_api_action.dart b/lib/action/invoke_api_action.dart
index df46f90be..0d1975e5d 100644
--- a/lib/action/invoke_api_action.dart
+++ b/lib/action/invoke_api_action.dart
@@ -224,13 +224,15 @@ class InvokeAPIController {
         EnsembleAction.fromYaml(apiDefinition['onError']);
     if (onErrorAction != null) {
       ScreenController().nowExecuteAction(
-          context, localizedContext, onErrorAction, apiMap, scopeManager, event: apiEvent);
+          context, localizedContext, onErrorAction, apiMap, scopeManager,
+          event: apiEvent);
     }
 
     // if our Action has onError, invoke that next
     if (action.onError != null) {
       ScreenController().nowExecuteAction(
-          context, localizedContext, action.onError!, apiMap, scopeManager, event: apiEvent);
+          context, localizedContext, action.onError!, apiMap, scopeManager,
+          event: apiEvent);
     }
 
     // silently fail if error handle is not defined? or should we alert user?
diff --git a/lib/framework/data_context.dart b/lib/framework/data_context.dart
index eb9f3a31e..0387d9e12 100644
--- a/lib/framework/data_context.dart
+++ b/lib/framework/data_context.dart
@@ -565,7 +565,7 @@ class Formatter with Invokable {
       'prettyCurrency': (input) => InvokablePrimitive.prettyCurrency(input),
       'prettyDuration': (input) =>
           InvokablePrimitive.prettyDuration(input, locale: locale),
-      'pluralize': pluralize
+      'pluralize': pluralize,
     };
   }
 
diff --git a/lib/framework/ensemble_widget.dart b/lib/framework/ensemble_widget.dart
index c1452cbce..f45ed55b2 100644
--- a/lib/framework/ensemble_widget.dart
+++ b/lib/framework/ensemble_widget.dart
@@ -1,16 +1,15 @@
 import 'package:ensemble_ts_interpreter/invokables/invokable.dart';
 import 'package:flutter/cupertino.dart';
 
-abstract class EnsembleWidget<C extends EnsembleController> extends StatefulWidget {
+abstract class EnsembleWidget<C extends EnsembleController>
+    extends StatefulWidget {
   const EnsembleWidget(this.controller, {super.key});
   final C controller;
 }
 
 abstract class EnsembleWidgetState<W extends EnsembleWidget> extends State<W> {
   void _update() {
-    setState(() {
-
-    });
+    setState(() {});
   }
 
   @override
@@ -32,4 +31,3 @@ abstract class EnsembleWidgetState<W extends EnsembleWidget> extends State<W> {
     super.dispose();
   }
 }
-
diff --git a/lib/framework/scope.dart b/lib/framework/scope.dart
index a1e659d21..819a82371 100644
--- a/lib/framework/scope.dart
+++ b/lib/framework/scope.dart
@@ -254,7 +254,8 @@ mixin ViewBuilder on IsScopeManager {
             if (model.inputs![param] != null) {
               // set the Custom Widget's inputs from parent scope
               evalPropertyAndRegisterBinding(
-                  scopeManager._parent!, // widget inputs are set in the parent's scope
+                  scopeManager
+                      ._parent!, // widget inputs are set in the parent's scope
                   payload.widget as Invokable,
                   param,
                   model.inputs![param]);
@@ -276,7 +277,8 @@ mixin ViewBuilder on IsScopeManager {
         // set props and styles on the widget. At this stage the widget
         // has not been attached, so no worries about ValueNotifier
         for (String key in model.props.keys) {
-          if (InvokableController.getSettableProperties(invokable).contains(key)) {
+          if (InvokableController.getSettableProperties(invokable)
+              .contains(key)) {
             if (_isPassthroughProperty(key, invokable)) {
               InvokableController.setProperty(invokable, key, model.props[key]);
             } else {
@@ -286,9 +288,11 @@ mixin ViewBuilder on IsScopeManager {
           }
         }
         for (String key in model.styles.keys) {
-          if (InvokableController.getSettableProperties(invokable).contains(key)) {
+          if (InvokableController.getSettableProperties(invokable)
+              .contains(key)) {
             if (_isPassthroughProperty(key, invokable)) {
-              InvokableController.setProperty(invokable, key, model.styles[key]);
+              InvokableController.setProperty(
+                  invokable, key, model.styles[key]);
             } else {
               evalPropertyAndRegisterBinding(
                   scopeManager, invokable, key, model.styles[key]);
diff --git a/lib/framework/widget/view_util.dart b/lib/framework/widget/view_util.dart
index 79cc5cadb..d399c3367 100644
--- a/lib/framework/widget/view_util.dart
+++ b/lib/framework/widget/view_util.dart
@@ -219,8 +219,7 @@ class ViewUtil {
       EnsembleController? previousController;
       String? id = model.props['id']?.toString();
       if (id != null) {
-        dynamic controller =
-            scopeNode.scope.dataContext.getContextById(id);
+        dynamic controller = scopeNode.scope.dataContext.getContextById(id);
         if (controller is EnsembleController) {
           previousController = controller;
         }
diff --git a/lib/widget/calendar.dart b/lib/widget/calendar.dart
index 11515d63f..ae7e00fd7 100644
--- a/lib/widget/calendar.dart
+++ b/lib/widget/calendar.dart
@@ -40,13 +40,13 @@ class EnsembleCalendar extends StatefulWidget
       'markedCell': () => _controller.markedDays.value
           .map((e) => e.toIso8601DateString())
           .toList(),
-      'disableCell': () => _controller.disableDays.value
+      'disabledCell': () => _controller.disableDays.value
           .map((e) => e.toIso8601DateString())
           .toList(),
       'rangeStart': () => _controller.rangeStart?.toIso8601DateString(),
       'rangeEnd': () => _controller.rangeEnd?.toIso8601DateString(),
       'range': () => _controller.range,
-      'focusDay': () => _controller.focusedDay.value,
+      'focusDate': () => _controller.focusedDay.value,
     };
   }
 
@@ -54,12 +54,20 @@ class EnsembleCalendar extends StatefulWidget
   Map<String, Function> methods() {
     return {
       'selectCell': (value) => _selectCell(value),
+      'toggleSelectCell': (value) => _toggleSelectedCell(value),
+      'unSelectCell': (value) => _unSelectCell(value),
       'markCell': (singleDate) => _markCell(singleDate),
+      'unMarkCell': (singleDate) => _unMarkCell(singleDate),
+      'toggleMarkCell': (singleDate) => _toggleMarkCell(singleDate),
       'disableCell': (value) => _disableCell(value),
+      'enableCell': (value) => _enableCell(value),
+      'toggleDisableCell': (value) => _toggleDisableCell(value),
       'previous': (value) => _controller.pageController?.previousPage(
           duration: const Duration(milliseconds: 300), curve: Curves.easeOut),
       'next': (value) => _controller.pageController?.nextPage(
-          duration: const Duration(milliseconds: 300), curve: Curves.easeOut)
+          duration: const Duration(milliseconds: 300), curve: Curves.easeOut),
+      'addRowSpan': (value) => setRowSpan(value),
+      'header': (value) => _controller.header,
     };
   }
 
@@ -133,6 +141,40 @@ class EnsembleCalendar extends StatefulWidget
     final rawDate = _getDate(value);
     if (rawDate == null) return;
 
+    HashSet<DateTime> updatedDisabledDays =
+        HashSet<DateTime>.from(_controller.disableDays.value);
+
+    for (var date in rawDate) {
+      updatedDisabledDays.add(date);
+    }
+
+    _controller.rangeStart = null;
+    _controller.rangeEnd = null;
+    _controller.range = null;
+    _controller.disableDays.value = updatedDisabledDays;
+  }
+
+  void _enableCell(dynamic value) {
+    final rawDate = _getDate(value);
+    if (rawDate == null) return;
+
+    HashSet<DateTime> updatedDisabledDays =
+        HashSet<DateTime>.from(_controller.disableDays.value);
+
+    for (var date in rawDate) {
+      updatedDisabledDays.remove(date);
+    }
+
+    _controller.rangeStart = null;
+    _controller.rangeEnd = null;
+    _controller.range = null;
+    _controller.disableDays.value = updatedDisabledDays;
+  }
+
+  void _toggleDisableCell(dynamic value) {
+    final rawDate = _getDate(value);
+    if (rawDate == null) return;
+
     HashSet<DateTime> updatedDisabledDays =
         HashSet<DateTime>.from(_controller.disableDays.value);
 
@@ -154,6 +196,40 @@ class EnsembleCalendar extends StatefulWidget
     final rawDate = _getDate(value);
     if (rawDate == null) return;
 
+    HashSet<DateTime> updatedDisabledDays =
+        HashSet<DateTime>.from(_controller.selectedDays.value);
+
+    for (var date in rawDate) {
+      updatedDisabledDays.add(date);
+    }
+
+    _controller.rangeStart = null;
+    _controller.rangeEnd = null;
+    _controller.range = null;
+    _controller.selectedDays.value = updatedDisabledDays;
+  }
+
+  void _unSelectCell(dynamic value) {
+    final rawDate = _getDate(value);
+    if (rawDate == null) return;
+
+    HashSet<DateTime> updatedDisabledDays =
+        HashSet<DateTime>.from(_controller.selectedDays.value);
+
+    for (var date in rawDate) {
+      updatedDisabledDays.remove(date);
+    }
+
+    _controller.rangeStart = null;
+    _controller.rangeEnd = null;
+    _controller.range = null;
+    _controller.selectedDays.value = updatedDisabledDays;
+  }
+
+  void _toggleSelectedCell(dynamic value) {
+    final rawDate = _getDate(value);
+    if (rawDate == null) return;
+
     HashSet<DateTime> updatedDisabledDays =
         HashSet<DateTime>.from(_controller.selectedDays.value);
 
@@ -171,10 +247,52 @@ class EnsembleCalendar extends StatefulWidget
     _controller.selectedDays.value = updatedDisabledDays;
   }
 
+  void _unMarkCell(dynamic value) {
+    final rawDate = _getDate(value);
+    if (rawDate == null) return;
+
+    HashSet<DateTime> updatedMarkDays =
+        HashSet<DateTime>.from(_controller.markedDays.value);
+    HashSet<DateTime> updatedSelectedDays =
+        HashSet<DateTime>.from(_controller.selectedDays.value);
+
+    for (var date in rawDate) {
+      updatedMarkDays.remove(date);
+      updatedSelectedDays.remove(date);
+    }
+
+    _controller.rangeStart = null;
+    _controller.rangeEnd = null;
+    _controller.range = null;
+    _controller.markedDays.value = updatedMarkDays;
+    _controller.selectedDays.value = updatedSelectedDays;
+  }
+
   void _markCell(dynamic value) {
     final rawDate = _getDate(value);
     if (rawDate == null) return;
 
+    HashSet<DateTime> updatedMarkDays =
+        HashSet<DateTime>.from(_controller.markedDays.value);
+    HashSet<DateTime> updatedSelectedDays =
+        HashSet<DateTime>.from(_controller.selectedDays.value);
+
+    for (var date in rawDate) {
+      updatedMarkDays.add(date);
+      updatedSelectedDays.remove(date);
+    }
+
+    _controller.rangeStart = null;
+    _controller.rangeEnd = null;
+    _controller.range = null;
+    _controller.markedDays.value = updatedMarkDays;
+    _controller.selectedDays.value = updatedSelectedDays;
+  }
+
+  void _toggleMarkCell(dynamic value) {
+    final rawDate = _getDate(value);
+    if (rawDate == null) return;
+
     HashSet<DateTime> updatedMarkDays =
         HashSet<DateTime>.from(_controller.markedDays.value);
     HashSet<DateTime> updatedSelectedDays =
@@ -197,14 +315,17 @@ class EnsembleCalendar extends StatefulWidget
   }
 
   void setRowSpan(dynamic data) {
-    if (data is YamlMap) {
+    final List<RowSpanConfig> spans = List.from(_controller.rowSpans.value);
+    if (data is YamlMap || data is Map) {
       final rowSpan = RowSpanConfig(
         startDay: Utils.getDate(data['start']),
         endDay: Utils.getDate(data['end']),
         widget: data['widget'],
+        inputs: data['inputs'],
       );
-      _controller.rowSpans.add(rowSpan);
+      spans.add(rowSpan);
     }
+    _controller.rowSpans.value = spans;
   }
 
   void setRangeData(dynamic data) {
@@ -244,13 +365,13 @@ class RowSpanConfig {
   DateTime? startDay;
   DateTime? endDay;
   dynamic widget;
-  Color? backgroundColor;
+  Map? inputs;
 
   RowSpanConfig({
     this.startDay,
     this.endDay,
     this.widget,
-    this.backgroundColor,
+    this.inputs,
   });
 
   bool get isValid => startDay != null && endDay != null;
@@ -309,10 +430,11 @@ class CalendarController extends WidgetController {
   EnsembleAction? onRangeStart;
   Color? highlightColor;
   bool headerVisible = true;
+  dynamic header;
   DateTime? firstDay;
   DateTime? lastDay;
   final ValueNotifier<DateTime> focusedDay = ValueNotifier(DateTime.now());
-  List<RowSpanConfig> rowSpans = [];
+  ValueNotifier<List<RowSpanConfig>> rowSpans = ValueNotifier([]);
   TextStyle? headerTextStyle;
 
   final ValueNotifier<Set<DateTime>> markedDays = ValueNotifier(
@@ -356,6 +478,10 @@ class CalendarState extends WidgetState<EnsembleCalendar> {
       setState(() {});
     });
 
+    widget._controller.rowSpans.addListener(() {
+      setState(() {});
+    });
+
     super.initState();
   }
 
@@ -428,22 +554,29 @@ class CalendarState extends WidgetState<EnsembleCalendar> {
           ValueListenableBuilder<DateTime>(
             valueListenable: widget._controller.focusedDay,
             builder: (context, value, _) {
-              return _CalendarHeader(
-                focusedDay: value,
-                headerStyle: widget._controller.headerTextStyle,
-                onLeftArrowTap: () {
-                  widget._controller.pageController?.previousPage(
-                    duration: const Duration(milliseconds: 300),
-                    curve: Curves.easeOut,
-                  );
-                },
-                onRightArrowTap: () {
-                  widget._controller.pageController?.nextPage(
-                    duration: const Duration(milliseconds: 300),
-                    curve: Curves.easeOut,
+              Widget? header;
+
+              if (widget._controller.header != null) {
+                header = widgetBuilder(context, widget._controller.header, {});
+              }
+
+              return header ??
+                  _CalendarHeader(
+                    focusedDay: value,
+                    headerStyle: widget._controller.headerTextStyle,
+                    onLeftArrowTap: () {
+                      widget._controller.pageController?.previousPage(
+                        duration: const Duration(milliseconds: 300),
+                        curve: Curves.easeOut,
+                      );
+                    },
+                    onRightArrowTap: () {
+                      widget._controller.pageController?.nextPage(
+                        duration: const Duration(milliseconds: 300),
+                        curve: Curves.easeOut,
+                      );
+                    },
                   );
-                },
-              );
             },
           ),
         TableCalendar(
@@ -470,18 +603,22 @@ class CalendarState extends WidgetState<EnsembleCalendar> {
           daysOfWeekVisible: true,
           overlayRanges: getOverlayRange(),
           calendarBuilders: CalendarBuilders(
-            overlayBuilder: widget._controller.rowSpans.isEmpty
+            overlayBuilder: widget._controller.rowSpans.value.isEmpty
                 ? null
                 : (context, range) {
                     final spans = widget._controller.rowSpans;
-                    for (var span in spans) {
+                    for (var span in spans.value) {
                       if (span.startDay == null || span.endDay == null) {
                         return const SizedBox.shrink();
                       }
                       if (DateTimeRange(
                               start: span.startDay!, end: span.endDay!) ==
                           range) {
-                        return widgetBuilder(context, span.widget, {});
+                        return widgetBuilder(
+                          context,
+                          span.widget,
+                          span.inputs?.cast<String, dynamic>() ?? {},
+                        );
                       }
                     }
                     return const SizedBox.shrink();
@@ -595,7 +732,7 @@ class CalendarState extends WidgetState<EnsembleCalendar> {
 
   List<DateTimeRange> getOverlayRange() {
     final overlayRange = <DateTimeRange>[];
-    for (var span in widget._controller.rowSpans) {
+    for (var span in widget._controller.rowSpans.value) {
       if (span.endDay != null && span.startDay != null) {
         overlayRange
             .add(DateTimeRange(start: span.startDay!, end: span.endDay!));
diff --git a/lib/widget/widget_registry.dart b/lib/widget/widget_registry.dart
index b88414bb7..40f27b91a 100644
--- a/lib/widget/widget_registry.dart
+++ b/lib/widget/widget_registry.dart
@@ -67,7 +67,7 @@ class WidgetRegistry {
   /// all statically-known widgets should be registered here.
   /// widgets can be dynamically registered (or overridden) by calling registerWidget()
   final Map<String, Function> _registeredWidgets = {
-      // TextWidget.type: TextWidget.build,
+    // TextWidget.type: TextWidget.build,
   };
 
   /// register or override a widget
@@ -77,10 +77,8 @@ class WidgetRegistry {
 
   Map<String, Function> get widgetMap => _registeredWidgets;
 
-
   /// Legacy: To be moved to _registeredWidgets;
-  static Map<String, Function> get legacyWidgetMap =>
-      <String, Function>{
+  static Map<String, Function> get legacyWidgetMap => <String, Function>{
         EnsembleText.type: () => EnsembleText(),
         Markdown.type: () => Markdown(),
         EnsembleHtml.type: () => EnsembleHtml(),