diff --git a/pkg/api/job_analysis.go b/pkg/api/job_analysis.go
index 9176e8705..4967aa2a8 100644
--- a/pkg/api/job_analysis.go
+++ b/pkg/api/job_analysis.go
@@ -109,6 +109,7 @@ func PrintJobAnalysisJSONFromDB(
 	}
 	tr := make([]testResult, 0)
 
+	// These matviews only contain data for the last ~14 days.
 	jr := dbc.DB.Table("prow_job_failed_tests_by_day_matview")
 	if period == PeriodHour {
 		jr = dbc.DB.Table("prow_job_failed_tests_by_hour_matview")
diff --git a/pkg/db/views.go b/pkg/db/views.go
index 43e3de881..27e891782 100644
--- a/pkg/db/views.go
+++ b/pkg/db/views.go
@@ -429,6 +429,7 @@ SELECT date_trunc('|||BY|||'::text, pjrt.prow_job_run_timestamp) AS period,
 FROM prow_job_run_tests pjrt
    JOIN tests tests ON pjrt.test_id = tests.id
 WHERE pjrt.status = 12
+  AND pjrt.prow_job_run_timestamp > (|||TIMENOW||| - '15 days'::interval)
 GROUP BY tests.name, (date_trunc('|||BY|||'::text, pjrt.prow_job_run_timestamp)), pjrt.prow_job_id
 `