diff --git a/ui/src/Components/Grid/AlertGrid/AlertGroup/Silence/index.test.js b/ui/src/Components/Grid/AlertGrid/AlertGroup/Silence/index.test.js
index 7071ed80b..e78c633e9 100644
--- a/ui/src/Components/Grid/AlertGrid/AlertGroup/Silence/index.test.js
+++ b/ui/src/Components/Grid/AlertGrid/AlertGroup/Silence/index.test.js
@@ -7,6 +7,7 @@ import { mount } from "enzyme";
 
 import toDiffableHtml from "diffable-html";
 
+import moment from "moment";
 import { advanceTo, clear } from "jest-date-mock";
 
 import { AlertStore } from "Stores/AlertStore";
@@ -52,7 +53,7 @@ let alertStore;
 let silenceFormStore;
 
 beforeEach(() => {
-  advanceTo(new Date(2000, 0, 1, 15, 0, 0));
+  advanceTo(moment.utc([2000, 0, 1, 15, 0, 0]));
   alertStore = new AlertStore([]);
   alertStore.data.upstreams = {
     counters: {
@@ -242,7 +243,7 @@ describe("<SilenceDetails />", () => {
   });
 
   it("expired silence endsAt label uses 'danger' class", () => {
-    advanceTo(new Date(2000, 0, 1, 23, 0, 0));
+    advanceTo(moment.utc([2000, 0, 1, 23, 0, 0]));
     const tree = MountedSilenceDetails(jest.fn());
     const endsAt = tree.find("span.badge").at(2);
     expect(endsAt.html()).toMatch(/text-danger/);
@@ -259,27 +260,27 @@ describe("<SilenceDetails />", () => {
 
 describe("<SilenceExpiryBadgeWithProgress />", () => {
   it("renders with class 'danger' and no progressbar when expired", () => {
-    advanceTo(new Date(2001, 0, 1, 23, 0, 0));
+    advanceTo(moment.utc([2001, 0, 1, 23, 0, 0]));
     const tree = MountedSilence(alertmanager);
     expect(tree.html()).toMatch(/badge-danger/);
     expect(tree.text()).toMatch(/Expired a year ago/);
   });
 
   it("progressbar uses class 'danger' when > 90%", () => {
-    advanceTo(new Date(2000, 0, 1, 19, 30, 0));
+    advanceTo(moment.utc([2000, 0, 1, 19, 30, 0]));
     const tree = MountedSilence(alertmanager);
     expect(tree.html()).toMatch(/progress-bar bg-danger/);
   });
 
   it("progressbar uses class 'danger' when > 75%", () => {
-    advanceTo(new Date(2000, 0, 1, 17, 45, 0));
+    advanceTo(moment.utc([2000, 0, 1, 17, 45, 0]));
     const tree = MountedSilence(alertmanager);
     expect(tree.html()).toMatch(/progress-bar bg-warning/);
   });
 
   it("calling calculate() on progress multiple times in a row doesn't change the value", () => {
-    const startsAt = new Date(2000, 0, 1, 10, 0, 0);
-    const endsAt = new Date(2000, 0, 1, 20, 0, 0);
+    const startsAt = moment.utc([2000, 0, 1, 10, 0, 0]);
+    const endsAt = moment.utc([2000, 0, 1, 20, 0, 0]);
 
     const tree = MountedSilence(alertmanager).find("Silence");
     const instance = tree.instance();
diff --git a/ui/src/Components/SilenceModal/PayloadPreview/index.test.js b/ui/src/Components/SilenceModal/PayloadPreview/index.test.js
index 3dafd53d1..4bef2df7d 100644
--- a/ui/src/Components/SilenceModal/PayloadPreview/index.test.js
+++ b/ui/src/Components/SilenceModal/PayloadPreview/index.test.js
@@ -12,8 +12,8 @@ import { PayloadPreview } from ".";
 describe("<PayloadPreview />", () => {
   it("matches snapshot", () => {
     const silenceFormStore = new SilenceFormStore();
-    silenceFormStore.data.startsAt = moment([2000, 1, 1, 0, 0, 0]);
-    silenceFormStore.data.endsAt = moment([2000, 1, 1, 1, 0, 0]);
+    silenceFormStore.data.startsAt = moment.utc([2000, 1, 1, 0, 0, 0]);
+    silenceFormStore.data.endsAt = moment.utc([2000, 1, 1, 1, 0, 0]);
     silenceFormStore.data.createdBy = "me@example.com";
     silenceFormStore.data.comment = "PayloadPreview test";
 
diff --git a/ui/src/Stores/SilenceFormStore.test.js b/ui/src/Stores/SilenceFormStore.test.js
index b8994373f..ea1b52e15 100644
--- a/ui/src/Stores/SilenceFormStore.test.js
+++ b/ui/src/Stores/SilenceFormStore.test.js
@@ -228,11 +228,11 @@ describe("SilenceFormStore.data", () => {
       })
     );
 
-    expect(store.data.startsAt.toISOString()).toBe(
-      moment([2000, 0, 1, 0, 0, 0]).toISOString()
+    expect(store.data.startsAt.utc().toISOString()).toBe(
+      moment.utc([2000, 0, 1, 0, 0, 0]).toISOString()
     );
-    expect(store.data.endsAt.toISOString()).toBe(
-      moment([2000, 0, 1, 1, 0, 0]).toISOString()
+    expect(store.data.endsAt.utc().toISOString()).toBe(
+      moment.utc([2000, 0, 1, 1, 0, 0]).toISOString()
     );
 
     expect(store.data.author).toBe("me@example.com");
@@ -256,8 +256,8 @@ describe("SilenceFormStore.data", () => {
     store.data.fillMatchersFromGroup(group);
     // add empty matcher so we test empty string rendering
     store.data.addEmptyMatcher();
-    store.data.startsAt = moment([2000, 1, 1, 0, 0, 0]);
-    store.data.endsAt = moment([2000, 1, 1, 1, 0, 0]);
+    store.data.startsAt = moment.utc([2000, 1, 1, 0, 0, 0]);
+    store.data.endsAt = moment.utc([2000, 1, 1, 1, 0, 0]);
     store.data.author = "me@example.com";
     store.data.comment = "toAlertmanagerPayload test";
     expect(store.data.toAlertmanagerPayload).toMatchSnapshot();