diff --git a/src/UpBlazor.ApiClient/UpBlazorClient.cs b/src/UpBlazor.ApiClient/UpBlazorClient.cs
index 13104a5..e7a0b42 100644
--- a/src/UpBlazor.ApiClient/UpBlazorClient.cs
+++ b/src/UpBlazor.ApiClient/UpBlazorClient.cs
@@ -4398,6 +4398,9 @@ public enum Interval
         [System.Runtime.Serialization.EnumMember(Value = @"Fortnights")]
         Fortnights = 2,
 
+        [System.Runtime.Serialization.EnumMember(Value = @"Monthly")]
+        Monthly = 3,
+
     }
 
     [System.CodeDom.Compiler.GeneratedCode("NJsonSchema", "13.18.0.0 (NJsonSchema v10.8.0.0 (Newtonsoft.Json v13.0.0.0))")]
diff --git a/src/UpBlazor.Application/Features/Forecast/GetExpenseForecastQuery.cs b/src/UpBlazor.Application/Features/Forecast/GetExpenseForecastQuery.cs
index 242956b..fd9ab6d 100644
--- a/src/UpBlazor.Application/Features/Forecast/GetExpenseForecastQuery.cs
+++ b/src/UpBlazor.Application/Features/Forecast/GetExpenseForecastQuery.cs
@@ -117,7 +117,13 @@ public async Task<IReadOnlyList<ForecastDto>> Handle(GetExpenseForecastQuery req
             {
                 if (expense.FromIncomeId is not null)
                 {
-                    var income = incomeCycleRanges.Keys.First(x => x == expense.FromIncomeId.Value);
+                    var income = incomeCycleRanges.Keys.FirstOrDefault(x => x == expense.FromIncomeId.Value);
+
+                    if (income == default)
+                    {
+                        // TODO: log this or delette the record
+                        continue;
+                    }
                     
                     var cycleCollision = incomeCycleRanges[income]
                         .FirstOrDefault(x => x == currentDay);
diff --git a/src/UpBlazor.Application/Features/Planner/GetIncomePlannerQuery.cs b/src/UpBlazor.Application/Features/Planner/GetIncomePlannerQuery.cs
index 0706e31..21c451b 100644
--- a/src/UpBlazor.Application/Features/Planner/GetIncomePlannerQuery.cs
+++ b/src/UpBlazor.Application/Features/Planner/GetIncomePlannerQuery.cs
@@ -183,9 +183,10 @@ private static void GetExactSubTotals(IncomePlannerDto output, IReadOnlyList<Sav
 
             var proRataAmount = recurringExpense.Amount * income.IntervalUnits * income.Interval switch
             {
-                Interval.Days => 1,
-                Interval.Weeks => 7,
-                Interval.Fortnights => 14,
+                Interval.Days => 1M,
+                Interval.Weeks => 7M,
+                Interval.Fortnights => 14M,
+                Interval.Monthly => 30.437M, // https://www.britannica.com/science/time/Lengths-of-years-and-months
                 _ => throw new ArgumentOutOfRangeException()
             };
 
diff --git a/src/UpBlazor.Core/Helpers/IntervalExtensions.cs b/src/UpBlazor.Core/Helpers/IntervalExtensions.cs
index 322f171..7c86ebc 100644
--- a/src/UpBlazor.Core/Helpers/IntervalExtensions.cs
+++ b/src/UpBlazor.Core/Helpers/IntervalExtensions.cs
@@ -13,6 +13,7 @@ interval switch
                 Interval.Days => TimeSpan.FromDays(units),
                 Interval.Weeks => TimeSpan.FromDays(units * 7),
                 Interval.Fortnights => TimeSpan.FromDays(units * 14),
+                Interval.Monthly => TimeSpan.FromDays(units * 30.437), // https://www.britannica.com/science/time/Lengths-of-years-and-months),
                 _ => throw new ArgumentOutOfRangeException(nameof(interval), interval, null)
             };
 
@@ -36,6 +37,29 @@ public static DateTime FindFirstCycle(this DateTime start, Interval interval, in
             return currentCycle;
         }
 
+        private static List<DateOnly> GetAllCyclesInMonthlyRange(this DateTime start, DateTime rangeStart,
+            DateTime rangeEnd, int units)
+        {
+            var dayOfMonth = start.Day;
+    
+            var output = new List<DateOnly>();
+
+            var potentialHit = new DateTime(start.Year, start.Month, dayOfMonth);
+
+            while (potentialHit <= rangeEnd)
+            {
+                if (potentialHit >= rangeStart)
+                {
+                    output.Add(DateOnly.FromDateTime(potentialHit));
+                }
+        
+                // Increment by the number of months specified in units
+                potentialHit = potentialHit.AddMonths(units);
+            }
+
+            return output;
+        }
+
         public static List<DateOnly> GetAllCyclesInRange(this DateTime start, DateTime rangeStart, DateTime rangeEnd, Interval interval, int units)
         {
             var startOfRange = start.FindFirstCycle(interval, units, rangeStart);
@@ -45,6 +69,11 @@ public static List<DateOnly> GetAllCyclesInRange(this DateTime start, DateTime r
             {
                 return Enumerable.Empty<DateOnly>().ToList();
             }
+            
+            if (interval is Interval.Monthly)
+            {
+                return GetAllCyclesInMonthlyRange(start, rangeStart, rangeEnd, units);
+            }
 
             var output = new List<DateOnly>
             {
diff --git a/src/UpBlazor.Core/Models/Enums/Interval.cs b/src/UpBlazor.Core/Models/Enums/Interval.cs
index ef61846..d4c0cf7 100644
--- a/src/UpBlazor.Core/Models/Enums/Interval.cs
+++ b/src/UpBlazor.Core/Models/Enums/Interval.cs
@@ -4,6 +4,7 @@ public enum Interval
     {
         Days,
         Weeks,
-        Fortnights
+        Fortnights,
+        Monthly
     }
 }
\ No newline at end of file
diff --git a/src/UpBlazor.Core/Models/Income.cs b/src/UpBlazor.Core/Models/Income.cs
index 6cfe45a..7239356 100644
--- a/src/UpBlazor.Core/Models/Income.cs
+++ b/src/UpBlazor.Core/Models/Income.cs
@@ -15,47 +15,5 @@ public class Income
         public int IntervalUnits { get; set; }
 
         public override string ToString() => $"{Name} (${ExactMoney:F2} every {IntervalUnits} {Interval})";
-
-        public bool FallsOn(DateTime dateTime, DateTime startDate, out int totalCyclesSinceStart)
-        {
-            var date = dateTime.Date;
-            
-            if (date < startDate)
-            {
-                totalCyclesSinceStart = default;
-                return false;
-            }
-
-            if (date == startDate)
-            {
-                totalCyclesSinceStart = 0;
-                return true;
-            }
-
-            var loopDate = startDate.Date;
-
-            totalCyclesSinceStart = 0;
-            
-            do
-            {
-                totalCyclesSinceStart++;
-                var toAdd = Interval switch
-                {
-                    Interval.Days => TimeSpan.FromDays(IntervalUnits),
-                    Interval.Fortnights => TimeSpan.FromDays(IntervalUnits * 14),
-                    Interval.Weeks => TimeSpan.FromDays(7),
-                    _ => throw new ArgumentOutOfRangeException()
-                };
-
-                loopDate = loopDate.Add(toAdd);
-
-                if (loopDate.Date == date.Date)
-                {
-                    return true;
-                }
-            } while (loopDate < date);
-
-            return false;
-        }
     }
 }
\ No newline at end of file
diff --git a/src/UpBlazor.Core/Models/RecurringExpense.cs b/src/UpBlazor.Core/Models/RecurringExpense.cs
index f1c81fd..20450d3 100644
--- a/src/UpBlazor.Core/Models/RecurringExpense.cs
+++ b/src/UpBlazor.Core/Models/RecurringExpense.cs
@@ -23,48 +23,5 @@ public string SaverId
             get => FromSaverId;
             set => FromSaverId = value;
         }
-        
-        public bool FallsOn(DateTime dateTime, DateTime startDate, out int totalCyclesSinceStart)
-        {
-            var date = dateTime.Date;
-            
-            if (date < startDate)
-            {
-                totalCyclesSinceStart = default;
-                return false;
-            }
-
-            if (date == startDate)
-            {
-                totalCyclesSinceStart = 0;
-                return true;
-            }
-
-            var loopDate = startDate.Date;
-
-            totalCyclesSinceStart = 0;
-            
-            do
-            {
-                totalCyclesSinceStart++;
-                var toAdd = Interval switch
-                {
-                    Interval.Days => TimeSpan.FromDays(IntervalUnits),
-                    Interval.Fortnights => TimeSpan.FromDays(IntervalUnits * 14),
-                    Interval.Weeks => TimeSpan.FromDays(7),
-                    _ => throw new ArgumentOutOfRangeException()
-                };
-
-                loopDate = loopDate.Add(toAdd);
-
-                if (loopDate.Date == date.Date)
-                {
-                    return true;
-                }
-            } while (loopDate < date);
-
-            return false;
-        }
-
     }
 }
\ No newline at end of file
diff --git a/src/UpBlazor.WebUI/Pages/Insights/Forecast/Index.razor b/src/UpBlazor.WebUI/Pages/Insights/Forecast/Index.razor
index dd53679..a3eacee 100644
--- a/src/UpBlazor.WebUI/Pages/Insights/Forecast/Index.razor
+++ b/src/UpBlazor.WebUI/Pages/Insights/Forecast/Index.razor
@@ -155,7 +155,9 @@ else
                         <ApexPointSeries TItem="ForecastDto"
                                          Items="@_totalForecastData.Where(x => x.AccountName == incomeName)"
                                          Name="@incomeName"
-                                         XValue="@(x => DateTime.ParseExact(x.Cycle, "dd/MM/yyyy", CultureInfo.InvariantCulture))"
+                                         XValue="@(x => 
+                                                 { 
+                                                     var date = DateOnly.ParseExact(x.Cycle, "dd/MM/yyyy", CultureInfo.InvariantCulture); return date.AddDays(1); })"
                                          YValue="x => x.Balance"/>
                     }
 
@@ -196,6 +198,7 @@ else
         Xaxis = new XAxis()
         {
             Type = XAxisType.Datetime,
+            TickPlacement = TickPlacement.On,
         },
         Yaxis = new List<YAxis>()
         {