diff --git a/x-pack/legacy/plugins/uptime/server/lib/adapters/monitor_states/__tests__/elasticsearch_monitor_states_adapter.test.ts b/x-pack/legacy/plugins/uptime/server/lib/adapters/monitor_states/__tests__/elasticsearch_monitor_states_adapter.test.ts
index 67a66362e4cc5..1a90699090b29 100644
--- a/x-pack/legacy/plugins/uptime/server/lib/adapters/monitor_states/__tests__/elasticsearch_monitor_states_adapter.test.ts
+++ b/x-pack/legacy/plugins/uptime/server/lib/adapters/monitor_states/__tests__/elasticsearch_monitor_states_adapter.test.ts
@@ -8,6 +8,8 @@ import { DatabaseAdapter } from '../../database';
 import exampleFilter from './example_filter.json';
 import monitorState from './monitor_states_docs.json';
 import { ElasticsearchMonitorStatesAdapter } from '../elasticsearch_monitor_states_adapter';
+import { get, set } from 'lodash';
+import { assertCloseTo } from '../../../helper';
 
 describe('ElasticsearchMonitorStatesAdapter', () => {
   let database: DatabaseAdapter;
@@ -37,6 +39,7 @@ describe('ElasticsearchMonitorStatesAdapter', () => {
   });
 
   it('applies an appropriate filter section to the query based on filters', async () => {
+    expect.assertions(3);
     const adapter = new ElasticsearchMonitorStatesAdapter(database);
     await adapter.legacyGetMonitorStates(
       {},
@@ -45,6 +48,28 @@ describe('ElasticsearchMonitorStatesAdapter', () => {
       JSON.stringify(exampleFilter),
       'down'
     );
+    expect(searchMock).toHaveBeenCalledTimes(3);
+    const fixedInterval = parseInt(
+      get(
+        searchMock.mock.calls[2][1],
+        'body.aggs.by_id.aggs.histogram.date_histogram.fixed_interval',
+        ''
+      ).split('ms')[0],
+      10
+    );
+    expect(fixedInterval).not.toBeNaN();
+    /**
+     * This value can sometimes be off by 1 as a result of fuzzy calculation.
+     *
+     * It had no implications in practice, but from a test standpoint can cause flaky
+     * snapshot failures.
+     */
+    assertCloseTo(fixedInterval, 36000, 100);
+    set(
+      searchMock.mock.calls[2][1],
+      'body.aggs.by_id.aggs.histogram.date_histogram.fixed_interval',
+      '36000ms'
+    );
     expect(searchMock.mock.calls).toMatchSnapshot();
   });
 });
diff --git a/x-pack/legacy/plugins/uptime/server/lib/adapters/monitors/__tests__/elasticsearch_monitors_adapter.test.ts b/x-pack/legacy/plugins/uptime/server/lib/adapters/monitors/__tests__/elasticsearch_monitors_adapter.test.ts
index 9fce667adf613..b21fb982bfb3b 100644
--- a/x-pack/legacy/plugins/uptime/server/lib/adapters/monitors/__tests__/elasticsearch_monitors_adapter.test.ts
+++ b/x-pack/legacy/plugins/uptime/server/lib/adapters/monitors/__tests__/elasticsearch_monitors_adapter.test.ts
@@ -8,12 +8,7 @@ import { get, set } from 'lodash';
 import { ElasticsearchMonitorsAdapter } from '../elasticsearch_monitors_adapter';
 import { CountParams, CountResponse } from 'elasticsearch';
 import mockChartsData from './monitor_charts_mock.json';
-
-const assertCloseTo = (actual: number, expected: number, precision: number) => {
-  if (Math.abs(expected - actual) > precision) {
-    throw new Error(`expected [${actual}] to be within ${precision} of ${actual}`);
-  }
-};
+import { assertCloseTo } from '../../../helper';
 
 // FIXME: there are many untested functions in this adapter. They should be tested.
 describe('ElasticsearchMonitorsAdapter', () => {
diff --git a/x-pack/legacy/plugins/uptime/server/lib/helper/__test__/__snapshots__/assert_close_to.test.ts.snap b/x-pack/legacy/plugins/uptime/server/lib/helper/__test__/__snapshots__/assert_close_to.test.ts.snap
new file mode 100644
index 0000000000000..7dfb8c88be1ca
--- /dev/null
+++ b/x-pack/legacy/plugins/uptime/server/lib/helper/__test__/__snapshots__/assert_close_to.test.ts.snap
@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`assertCloseTo throws an error when expected value is outside of precision range 1`] = `"expected [12500] to be within 100 of 10000"`;
diff --git a/x-pack/legacy/plugins/uptime/server/lib/helper/__test__/assert_close_to.test.ts b/x-pack/legacy/plugins/uptime/server/lib/helper/__test__/assert_close_to.test.ts
new file mode 100644
index 0000000000000..6ccedcf7153dc
--- /dev/null
+++ b/x-pack/legacy/plugins/uptime/server/lib/helper/__test__/assert_close_to.test.ts
@@ -0,0 +1,21 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import { assertCloseTo } from '../assert_close_to';
+
+describe('assertCloseTo', () => {
+  it('does not throw an error when expected value is correct', () => {
+    assertCloseTo(10000, 10001, 100);
+  });
+
+  it('does not throw an error when expected value is under actual, but within precision threshold', () => {
+    assertCloseTo(10000, 9875, 300);
+  });
+
+  it('throws an error when expected value is outside of precision range', () => {
+    expect(() => assertCloseTo(10000, 12500, 100)).toThrowErrorMatchingSnapshot();
+  });
+});
diff --git a/x-pack/legacy/plugins/uptime/server/lib/helper/assert_close_to.ts b/x-pack/legacy/plugins/uptime/server/lib/helper/assert_close_to.ts
new file mode 100644
index 0000000000000..13b6f3688809c
--- /dev/null
+++ b/x-pack/legacy/plugins/uptime/server/lib/helper/assert_close_to.ts
@@ -0,0 +1,11 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+export const assertCloseTo = (actual: number, expected: number, precision: number) => {
+  if (Math.abs(expected - actual) > precision) {
+    throw new Error(`expected [${expected}] to be within ${precision} of ${actual}`);
+  }
+};
diff --git a/x-pack/legacy/plugins/uptime/server/lib/helper/index.ts b/x-pack/legacy/plugins/uptime/server/lib/helper/index.ts
index 19d5a3b00237d..a2a72825c6b98 100644
--- a/x-pack/legacy/plugins/uptime/server/lib/helper/index.ts
+++ b/x-pack/legacy/plugins/uptime/server/lib/helper/index.ts
@@ -9,3 +9,4 @@ export { formatEsBucketsForHistogram } from './format_es_buckets_for_histogram';
 export { getFilterClause } from './get_filter_clause';
 export { getHistogramInterval } from './get_histogram_interval';
 export { parseFilterQuery } from './parse_filter_query';
+export { assertCloseTo } from './assert_close_to';