diff --git a/src/core_plugins/kibana/public/context/api/__tests__/predecessors.js b/src/core_plugins/kibana/public/context/api/__tests__/predecessors.js
index 2e461ff836fe..7caeec57f4cf 100644
--- a/src/core_plugins/kibana/public/context/api/__tests__/predecessors.js
+++ b/src/core_plugins/kibana/public/context/api/__tests__/predecessors.js
@@ -103,7 +103,7 @@ describe('context app', function () {
           // should have started at the given time
           expect(intervals[0].gte).to.eql(MS_PER_DAY * 3000);
           // should have ended with a half-open interval
-          expect(_.last(intervals)).to.only.have.key('gte');
+          expect(_.last(intervals)).to.only.have.keys('gte', 'format');
           expect(intervals.length).to.be.greaterThan(1);
 
           expect(hits).to.eql(searchSourceStub._stubHits.slice(0, 3));
diff --git a/src/core_plugins/kibana/public/context/api/__tests__/successors.js b/src/core_plugins/kibana/public/context/api/__tests__/successors.js
index 1974d55655e2..e9c3e94829b7 100644
--- a/src/core_plugins/kibana/public/context/api/__tests__/successors.js
+++ b/src/core_plugins/kibana/public/context/api/__tests__/successors.js
@@ -103,7 +103,7 @@ describe('context app', function () {
           // should have started at the given time
           expect(intervals[0].lte).to.eql(MS_PER_DAY * 3000);
           // should have ended with a half-open interval
-          expect(_.last(intervals)).to.only.have.key('lte');
+          expect(_.last(intervals)).to.only.have.keys('lte', 'format');
           expect(intervals.length).to.be.greaterThan(1);
 
           expect(hits).to.eql(searchSourceStub._stubHits.slice(-3));
diff --git a/src/core_plugins/kibana/public/context/api/context.js b/src/core_plugins/kibana/public/context/api/context.js
index 68ca81e83a20..6b60eea7b767 100644
--- a/src/core_plugins/kibana/public/context/api/context.js
+++ b/src/core_plugins/kibana/public/context/api/context.js
@@ -216,6 +216,7 @@ function fetchContextProvider(indexPatterns, Private) {
             filter: {
               range: {
                 [timeField]: {
+                  format: 'epoch_millis',
                   ...startRange,
                   ...endRange,
                 }