diff --git a/src/commands/apps/list.ts b/src/commands/apps/list.ts
index 7a38e96a..187c8520 100644
--- a/src/commands/apps/list.ts
+++ b/src/commands/apps/list.ts
@@ -39,6 +39,8 @@ export default class AppsList extends ControlBaseCommand {
           // Mark current app in JSON output
           const appsWithCurrentFlag = apps.map((app) => ({
             ...app,
+            created: new Date(app.created).toISOString(),
+            modified: new Date(app.modified).toISOString(),
             isCurrent: app.id === currentAppId,
           }));
 
diff --git a/src/commands/auth/keys/create.ts b/src/commands/auth/keys/create.ts
index 34577f61..39616227 100644
--- a/src/commands/auth/keys/create.ts
+++ b/src/commands/auth/keys/create.ts
@@ -76,6 +76,8 @@ export default class KeysCreateCommand extends ControlBaseCommand {
           {
             key: {
               ...key,
+              created: new Date(key.created).toISOString(),
+              modified: new Date(key.modified).toISOString(),
               keyName: `${key.appId}.${key.id}`,
             },
           },
diff --git a/src/commands/auth/keys/get.ts b/src/commands/auth/keys/get.ts
index 63808b96..949d6a78 100644
--- a/src/commands/auth/keys/get.ts
+++ b/src/commands/auth/keys/get.ts
@@ -93,6 +93,8 @@ export default class KeysGetCommand extends ControlBaseCommand {
           {
             key: {
               ...key,
+              created: new Date(key.created).toISOString(),
+              modified: new Date(key.modified).toISOString(),
               keyName,
               ...(hasEnvOverride
                 ? {
diff --git a/src/commands/auth/keys/list.ts b/src/commands/auth/keys/list.ts
index 59d8b3aa..3dda5492 100644
--- a/src/commands/auth/keys/list.ts
+++ b/src/commands/auth/keys/list.ts
@@ -64,6 +64,8 @@ export default class KeysListCommand extends ControlBaseCommand {
           const keyName = `${key.appId}.${key.id}`;
           return {
             ...key,
+            created: new Date(key.created).toISOString(),
+            modified: new Date(key.modified).toISOString(),
             current: keyName === currentKeyName,
             keyName, // Add the full key name
           };
diff --git a/src/commands/channels/history.ts b/src/commands/channels/history.ts
index 104008eb..34f6bf36 100644
--- a/src/commands/channels/history.ts
+++ b/src/commands/channels/history.ts
@@ -129,7 +129,16 @@ export default class ChannelsHistory extends AblyBaseCommand {
         const lastTimestamp =
           messages.length > 0 ? messages.at(-1)!.timestamp : undefined;
         const next = buildPaginationNext(hasMore, lastTimestamp);
-        this.logJsonResult({ messages, hasMore, ...(next && { next }) }, flags);
+        const jsonMessages = messages.map((msg) => ({
+          ...msg,
+          timestamp: msg.timestamp
+            ? new Date(msg.timestamp).toISOString()
+            : undefined,
+        }));
+        this.logJsonResult(
+          { messages: jsonMessages, hasMore, ...(next && { next }) },
+          flags,
+        );
       } else {
         if (messages.length === 0) {
           this.log("No messages found in the channel history.");
diff --git a/src/commands/integrations/create.ts b/src/commands/integrations/create.ts
index f6682b8d..6664811e 100644
--- a/src/commands/integrations/create.ts
+++ b/src/commands/integrations/create.ts
@@ -150,7 +150,16 @@ export default class IntegrationsCreateCommand extends ControlBaseCommand {
       );
 
       if (this.shouldOutputJson(flags)) {
-        this.logJsonResult({ integration: createdIntegration }, flags);
+        this.logJsonResult(
+          {
+            integration: {
+              ...createdIntegration,
+              created: new Date(createdIntegration.created).toISOString(),
+              modified: new Date(createdIntegration.modified).toISOString(),
+            },
+          },
+          flags,
+        );
       } else {
         this.log(
           formatSuccess(
diff --git a/src/commands/integrations/get.ts b/src/commands/integrations/get.ts
index 906c638b..990abae7 100644
--- a/src/commands/integrations/get.ts
+++ b/src/commands/integrations/get.ts
@@ -41,12 +41,13 @@ export default class IntegrationsGetCommand extends ControlBaseCommand {
       const rule = await controlApi.getRule(appId, args.ruleId);
 
       if (this.shouldOutputJson(flags)) {
-        this.logJsonResult(
-          {
-            rule: structuredClone(rule) as unknown as Record<string, unknown>,
-          },
-          flags,
-        );
+        const ruleClone = structuredClone(rule) as unknown as Record<
+          string,
+          unknown
+        >;
+        ruleClone.created = new Date(rule.created).toISOString();
+        ruleClone.modified = new Date(rule.modified).toISOString();
+        this.logJsonResult({ rule: ruleClone }, flags);
       } else {
         this.log(formatHeading("Integration Rule Details"));
         this.log(`${formatLabel("ID")} ${rule.id}`);
diff --git a/src/commands/integrations/update.ts b/src/commands/integrations/update.ts
index 832fde4e..cc9feffc 100644
--- a/src/commands/integrations/update.ts
+++ b/src/commands/integrations/update.ts
@@ -107,7 +107,16 @@ export default class IntegrationsUpdateCommand extends ControlBaseCommand {
       );
 
       if (this.shouldOutputJson(flags)) {
-        this.logJsonResult({ rule: updatedRule }, flags);
+        this.logJsonResult(
+          {
+            rule: {
+              ...updatedRule,
+              created: new Date(updatedRule.created).toISOString(),
+              modified: new Date(updatedRule.modified).toISOString(),
+            },
+          },
+          flags,
+        );
       } else {
         this.log(formatSuccess("Integration rule updated."));
         this.log(`ID: ${updatedRule.id}`);
diff --git a/src/commands/rooms/messages/history.ts b/src/commands/rooms/messages/history.ts
index 20197c58..64e2f8a2 100644
--- a/src/commands/rooms/messages/history.ts
+++ b/src/commands/rooms/messages/history.ts
@@ -165,7 +165,7 @@ export default class MessagesHistory extends ChatBaseCommand {
             messages: items.map((message) => ({
               clientId: message.clientId,
               text: message.text,
-              timestamp: message.timestamp,
+              timestamp: message.timestamp.toISOString(),
               serial: message.serial,
               action: String(message.action),
               ...(message.metadata ? { metadata: message.metadata } : {}),
diff --git a/src/commands/rooms/messages/subscribe.ts b/src/commands/rooms/messages/subscribe.ts
index 8958dfce..acee6fb4 100644
--- a/src/commands/rooms/messages/subscribe.ts
+++ b/src/commands/rooms/messages/subscribe.ts
@@ -19,7 +19,7 @@ import {
 interface ChatMessage {
   clientId: string;
   text: string;
-  timestamp: number | Date; // Support both timestamp types
+  timestamp: string;
   serial: string;
   action: string;
   metadata?: Record<string, unknown>;
@@ -100,7 +100,7 @@ export default class MessagesSubscribe extends ChatBaseCommand {
       const messageLog: ChatMessage = {
         clientId: message.clientId,
         text: message.text,
-        timestamp: message.timestamp,
+        timestamp: message.timestamp.toISOString(),
         serial: message.serial,
         action: String(messageEvent.type),
         ...(message.metadata ? { metadata: message.metadata } : {}),
diff --git a/src/commands/spaces/get.ts b/src/commands/spaces/get.ts
index 5044ee35..b92b42ff 100644
--- a/src/commands/spaces/get.ts
+++ b/src/commands/spaces/get.ts
@@ -9,7 +9,6 @@ import {
   formatHeading,
   formatIndex,
   formatLabel,
-  formatMessageTimestamp,
   formatProgress,
   formatResource,
 } from "../../utils/output.js";
@@ -116,7 +115,10 @@ export default class SpacesGet extends SpacesBaseCommand {
           isConnected: action !== "leave" && action !== "absent",
           profileData: item.data?.profileUpdate?.current ?? null,
           location: item.data?.locationUpdate?.current ?? null,
-          lastEvent: { name: action, timestamp: item.timestamp },
+          lastEvent: {
+            name: action,
+            timestamp: new Date(item.timestamp).toISOString(),
+          },
         };
       });
 
@@ -163,7 +165,7 @@ export default class SpacesGet extends SpacesBaseCommand {
             `  ${formatLabel("Last Event")} ${formatEventType(member.lastEvent.name)}`,
           );
           this.log(
-            `  ${formatLabel("Event Timestamp")} ${formatMessageTimestamp(member.lastEvent.timestamp)}`,
+            `  ${formatLabel("Event Timestamp")} ${member.lastEvent.timestamp}`,
           );
           this.log("");
         }
diff --git a/src/control-base-command.ts b/src/control-base-command.ts
index 8acf2151..f8db353f 100644
--- a/src/control-base-command.ts
+++ b/src/control-base-command.ts
@@ -58,7 +58,7 @@ export abstract class ControlBaseCommand extends AblyBaseCommand {
   }
 
   protected formatDate(timestamp: number): string {
-    return new Date(timestamp).toLocaleString();
+    return new Date(timestamp).toISOString();
   }
 
   /**
diff --git a/src/utils/spaces-output.ts b/src/utils/spaces-output.ts
index 32c559bc..67d871d1 100644
--- a/src/utils/spaces-output.ts
+++ b/src/utils/spaces-output.ts
@@ -16,7 +16,7 @@ export interface MemberOutput {
   isConnected: boolean;
   profileData: Record<string, unknown> | null;
   location: unknown | null;
-  lastEvent: { name: string; timestamp: number };
+  lastEvent: { name: string; timestamp: string };
 }
 
 export interface CursorOutput {
@@ -30,7 +30,7 @@ export interface LockOutput {
   id: string;
   status: string;
   member: MemberOutput;
-  timestamp: number;
+  timestamp: string;
   attributes: Record<string, unknown> | null;
   reason: { message?: string; code?: number; statusCode?: number } | null;
 }
@@ -51,7 +51,7 @@ export function formatMemberOutput(member: SpaceMember): MemberOutput {
     location: member.location ?? null,
     lastEvent: {
       name: member.lastEvent.name,
-      timestamp: member.lastEvent.timestamp,
+      timestamp: new Date(member.lastEvent.timestamp).toISOString(),
     },
   };
 }
@@ -70,7 +70,7 @@ export function formatLockOutput(lock: Lock): LockOutput {
     id: lock.id,
     status: lock.status,
     member: formatMemberOutput(lock.member),
-    timestamp: lock.timestamp,
+    timestamp: new Date(lock.timestamp).toISOString(),
     attributes: (lock.attributes as Record<string, unknown>) ?? null,
     reason: lock.reason
       ? {
diff --git a/test/unit/commands/apps/create.test.ts b/test/unit/commands/apps/create.test.ts
index 9e9e8d53..06d48ba7 100644
--- a/test/unit/commands/apps/create.test.ts
+++ b/test/unit/commands/apps/create.test.ts
@@ -67,6 +67,7 @@ describe("apps:create command", () => {
       expect(stdout).toContain(newAppId);
       expect(stdout).toContain(mockAppName);
       expect(stdout).toContain("Automatically switched to app");
+      expect(stdout).toMatch(/\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z/);
     });
 
     it("should create an app with TLS only flag", async () => {
diff --git a/test/unit/commands/apps/list.test.ts b/test/unit/commands/apps/list.test.ts
index da8a4790..0140cd50 100644
--- a/test/unit/commands/apps/list.test.ts
+++ b/test/unit/commands/apps/list.test.ts
@@ -106,6 +106,8 @@ describe("apps:list command", () => {
         "550e8400-e29b-41d4-a716-446655440001",
       );
       expect(result.apps[1]).toHaveProperty("name", "Test App 2");
+      expect(result.apps[0].created).toBe("2022-01-01T00:00:00.000Z");
+      expect(result.apps[0].modified).toBe("2022-01-01T00:00:00.000Z");
     });
 
     it("should handle empty apps list", async () => {
diff --git a/test/unit/commands/auth/keys/create.test.ts b/test/unit/commands/auth/keys/create.test.ts
index e0cd071d..9770cf0c 100644
--- a/test/unit/commands/auth/keys/create.test.ts
+++ b/test/unit/commands/auth/keys/create.test.ts
@@ -147,6 +147,12 @@ describe("auth:keys:create command", () => {
       expect(result.key).toHaveProperty("id", mockKeyId);
       expect(result.key).toHaveProperty("name", "TestKey");
       expect(result.key).toHaveProperty("key");
+      expect(result.key.created).toMatch(
+        /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/,
+      );
+      expect(result.key.modified).toMatch(
+        /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/,
+      );
     });
 
     it("should use ABLY_ACCESS_TOKEN environment variable when provided", async () => {
diff --git a/test/unit/commands/auth/keys/get.test.ts b/test/unit/commands/auth/keys/get.test.ts
index b3a653cb..a04487c3 100644
--- a/test/unit/commands/auth/keys/get.test.ts
+++ b/test/unit/commands/auth/keys/get.test.ts
@@ -128,6 +128,12 @@ describe("auth:keys:get command", () => {
       expect(result).toHaveProperty("success", true);
       expect(result).toHaveProperty("key");
       expect(result.key).toHaveProperty("id", mockKeyId);
+      expect(result.key.created).toMatch(
+        /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/,
+      );
+      expect(result.key.modified).toMatch(
+        /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/,
+      );
     });
 
     it("should show warning when fetched key is current and ABLY_API_KEY env var overrides it", async () => {
diff --git a/test/unit/commands/auth/keys/list.test.ts b/test/unit/commands/auth/keys/list.test.ts
index ba7c8544..66f8f9a0 100644
--- a/test/unit/commands/auth/keys/list.test.ts
+++ b/test/unit/commands/auth/keys/list.test.ts
@@ -158,6 +158,12 @@ describe("auth:keys:list command", () => {
       expect(result).toHaveProperty("keys");
       expect(result.keys).toHaveLength(1);
       expect(result.keys[0]).toHaveProperty("name", "Test Key");
+      expect(result.keys[0].created).toMatch(
+        /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/,
+      );
+      expect(result.keys[0].modified).toMatch(
+        /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/,
+      );
     });
   });
 
diff --git a/test/unit/commands/channels/history.test.ts b/test/unit/commands/channels/history.test.ts
index 57d717c0..d4512b6a 100644
--- a/test/unit/commands/channels/history.test.ts
+++ b/test/unit/commands/channels/history.test.ts
@@ -182,6 +182,7 @@ describe("channels:history command", () => {
       expect(messages[0]).toHaveProperty("name", "test-event");
       expect(messages[0]).toHaveProperty("data");
       expect(messages[0].data).toEqual({ text: "Hello world" });
+      expect(messages[0].timestamp).toBe("2023-11-14T22:13:20.000Z");
     });
   });
 
diff --git a/test/unit/commands/integrations/create.test.ts b/test/unit/commands/integrations/create.test.ts
index aff8ac55..ba11738a 100644
--- a/test/unit/commands/integrations/create.test.ts
+++ b/test/unit/commands/integrations/create.test.ts
@@ -115,6 +115,8 @@ describe("integrations:create command", () => {
             url: "https://example.com/webhook",
           },
           status: "disabled",
+          created: 1640995200000,
+          modified: 1640995200000,
         });
 
       const { stdout } = await runCommand(
@@ -159,6 +161,8 @@ describe("integrations:create command", () => {
             url: "https://example.com/webhook",
           },
           status: "enabled",
+          created: 1640995200000,
+          modified: 1640995200000,
         });
 
       const { stdout } = await runCommand(
@@ -202,6 +206,8 @@ describe("integrations:create command", () => {
             format: "json",
           },
           status: "enabled",
+          created: 1640995200000,
+          modified: 1640995200000,
         });
 
       const { stdout } = await runCommand(
@@ -227,6 +233,12 @@ describe("integrations:create command", () => {
       expect(result).toHaveProperty("integration");
       expect(result.integration).toHaveProperty("id", mockRuleId);
       expect(result.integration).toHaveProperty("ruleType", "http");
+      expect(result.integration.created).toMatch(
+        /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/,
+      );
+      expect(result.integration.modified).toMatch(
+        /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/,
+      );
     });
   });
 
@@ -352,6 +364,8 @@ describe("integrations:create command", () => {
             url: "https://example.com/webhook",
           },
           status: "enabled",
+          created: 1640995200000,
+          modified: 1640995200000,
         });
 
       const { stdout } = await runCommand(
@@ -392,6 +406,8 @@ describe("integrations:create command", () => {
             url: "https://example.com/webhook",
           },
           status: "enabled",
+          created: 1640995200000,
+          modified: 1640995200000,
         });
 
       const { stdout } = await runCommand(
diff --git a/test/unit/commands/integrations/get.test.ts b/test/unit/commands/integrations/get.test.ts
index cfb3ac9c..d41613e3 100644
--- a/test/unit/commands/integrations/get.test.ts
+++ b/test/unit/commands/integrations/get.test.ts
@@ -95,6 +95,12 @@ describe("integrations:get command", () => {
       expect(result.rule).toHaveProperty("ruleType", "http");
       expect(result.rule).toHaveProperty("source");
       expect(result.rule.source).toHaveProperty("type", "channel.message");
+      expect(result.rule.created).toMatch(
+        /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/,
+      );
+      expect(result.rule.modified).toMatch(
+        /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/,
+      );
     });
 
     it("should output pretty JSON when --pretty-json flag is used", async () => {
diff --git a/test/unit/commands/integrations/update.test.ts b/test/unit/commands/integrations/update.test.ts
index 0b99f22e..81f84242 100644
--- a/test/unit/commands/integrations/update.test.ts
+++ b/test/unit/commands/integrations/update.test.ts
@@ -167,6 +167,12 @@ describe("integrations:update command", () => {
       expect(result).toHaveProperty("success", true);
       expect(result).toHaveProperty("rule");
       expect(result.rule).toHaveProperty("id", mockRuleId);
+      expect(result.rule.created).toMatch(
+        /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/,
+      );
+      expect(result.rule.modified).toMatch(
+        /^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d{3}Z$/,
+      );
     });
 
     it("should update request mode", async () => {