diff --git a/src/controllers/api/updateChallengeProgressController.ts b/src/controllers/api/updateChallengeProgressController.ts
index 68ae6c55..b75e820a 100644
--- a/src/controllers/api/updateChallengeProgressController.ts
+++ b/src/controllers/api/updateChallengeProgressController.ts
@@ -1,7 +1,7 @@
 import { RequestHandler } from "express";
 import { getJSONfromString } from "@/src/helpers/stringHelpers";
 import { getAccountForRequest } from "@/src/services/loginService";
-import { addChallenges, getInventory } from "@/src/services/inventoryService";
+import { addCalendarProgress, addChallenges, getInventory } from "@/src/services/inventoryService";
 import { IChallengeProgress, ISeasonChallenge } from "@/src/types/inventoryTypes/inventoryTypes";
 import { IAffiliationMods } from "@/src/types/purchaseTypes";
 import { getEntriesUnsafe } from "@/src/utils/ts-utils";
@@ -25,13 +25,17 @@ export const updateChallengeProgressController: RequestHandler = async (req, res
         );
     }
     for (const [key, value] of getEntriesUnsafe(challenges)) {
+        if (value === undefined) {
+            logger.error(`Challenge progress update key ${key} has no value`);
+            continue;
+        }
         switch (key) {
             case "ChallengesFixVersion":
                 inventory.ChallengesFixVersion = value;
                 break;
 
             case "SeasonChallengeHistory":
-                value!.forEach(({ challenge, id }) => {
+                value.forEach(({ challenge, id }) => {
                     const itemIndex = inventory.SeasonChallengeHistory.findIndex(i => i.challenge === challenge);
                     if (itemIndex !== -1) {
                         inventory.SeasonChallengeHistory[itemIndex].id = id;
@@ -41,6 +45,10 @@ export const updateChallengeProgressController: RequestHandler = async (req, res
                 });
                 break;
 
+            case "CalendarProgress":
+                addCalendarProgress(inventory, value);
+                break;
+
             case "ChallengeProgress":
             case "SeasonChallengeCompletions":
             case "ChallengePTS":
@@ -63,5 +71,6 @@ interface IUpdateChallengeProgressRequest {
     ChallengeProgress?: IChallengeProgress[];
     SeasonChallengeHistory?: ISeasonChallenge[];
     SeasonChallengeCompletions?: ISeasonChallenge[];
+    CalendarProgress?: { challenge: string }[];
     crossPlaySetting?: string;
 }
diff --git a/src/services/inventoryService.ts b/src/services/inventoryService.ts
index cf5208ce..fafbca6c 100644
--- a/src/services/inventoryService.ts
+++ b/src/services/inventoryService.ts
@@ -1832,6 +1832,15 @@ export const addChallenges = (
     return affiliationMods;
 };
 
+export const addCalendarProgress = (inventory: TInventoryDatabaseDocument, value: { challenge: string }[]): void => {
+    const calendarProgress = getCalendarProgress(inventory);
+    const currentSeason = getWorldState().KnownCalendarSeasons[0];
+    calendarProgress.SeasonProgress.LastCompletedChallengeDayIdx = currentSeason.Days.findIndex(
+        day => day.events.length != 0 && day.events[0].challenge == value[value.length - 1].challenge
+    );
+    checkCalendarChallengeCompletion(calendarProgress, currentSeason);
+};
+
 export const addMissionComplete = (inventory: TInventoryDatabaseDocument, { Tag, Completes, Tier }: IMission): void => {
     const { Missions } = inventory;
     const itemIndex = Missions.findIndex(item => item.Tag === Tag);
diff --git a/src/services/missionInventoryUpdateService.ts b/src/services/missionInventoryUpdateService.ts
index c4a62f2c..09bdc1c6 100644
--- a/src/services/missionInventoryUpdateService.ts
+++ b/src/services/missionInventoryUpdateService.ts
@@ -14,6 +14,7 @@ import { IRngResult, SRng, getRandomElement, getRandomReward } from "@/src/servi
 import { equipmentKeys, IMission, ITypeCount, TEquipmentKey } from "@/src/types/inventoryTypes/inventoryTypes";
 import {
     addBooster,
+    addCalendarProgress,
     addChallenges,
     addConsumables,
     addCrewShipAmmo,
@@ -33,10 +34,8 @@ import {
     addSkin,
     addStanding,
     applyClientEquipmentUpdates,
-    checkCalendarChallengeCompletion,
     combineInventoryChanges,
     generateRewardSeed,
-    getCalendarProgress,
     getDialogue,
     giveNemesisPetRecipe,
     giveNemesisWeaponRecipe,
@@ -235,7 +234,7 @@ export const addMissionInventoryUpdates = async (
     }
     for (const [key, value] of getEntriesUnsafe(inventoryUpdates)) {
         if (value === undefined) {
-            logger.error(`Inventory update key ${key} has no value `);
+            logger.error(`Inventory update key ${key} has no value`);
             continue;
         }
         switch (key) {
@@ -671,12 +670,7 @@ export const addMissionInventoryUpdates = async (
                 break;
             }
             case "CalendarProgress": {
-                const calendarProgress = getCalendarProgress(inventory);
-                const currentSeason = getWorldState().KnownCalendarSeasons[0];
-                calendarProgress.SeasonProgress.LastCompletedChallengeDayIdx = currentSeason.Days.findIndex(
-                    day => day.events.length != 0 && day.events[0].challenge == value[value.length - 1].challenge
-                );
-                checkCalendarChallengeCompletion(calendarProgress, currentSeason);
+                addCalendarProgress(inventory, value);
                 break;
             }
             case "duviriCaveOffers": {