diff --git a/app/vmselect/promql/eval.go b/app/vmselect/promql/eval.go
index 1494b825ed..4398c59b6d 100644
--- a/app/vmselect/promql/eval.go
+++ b/app/vmselect/promql/eval.go
@@ -1287,7 +1287,7 @@ func evalInstantRollup(qt *querytracer.Tracer, ec *EvalConfig, funcName string,
 			return evalAt(qtChild, timestamp, window)
 		}
 		// Calculate the result
-		tss, ok := getMaxInstantValues(qtChild, tssCached, tssStart, tssEnd)
+		tss, ok := getMaxInstantValues(qtChild, tssCached, tssStart, tssEnd, timestamp)
 		if !ok {
 			qtChild.Printf("cannot apply instant rollup optimization, since tssEnd contains bigger values than tssCached")
 			deleteCachedSeries(qtChild)
@@ -1349,7 +1349,7 @@ func evalInstantRollup(qt *querytracer.Tracer, ec *EvalConfig, funcName string,
 			return evalAt(qtChild, timestamp, window)
 		}
 		// Calculate the result
-		tss, ok := getMinInstantValues(qtChild, tssCached, tssStart, tssEnd)
+		tss, ok := getMinInstantValues(qtChild, tssCached, tssStart, tssEnd, timestamp)
 		if !ok {
 			qtChild.Printf("cannot apply instant rollup optimization, since tssEnd contains smaller values than tssCached")
 			deleteCachedSeries(qtChild)
@@ -1414,7 +1414,7 @@ func evalInstantRollup(qt *querytracer.Tracer, ec *EvalConfig, funcName string,
 			return evalAt(qtChild, timestamp, window)
 		}
 		// Calculate the result
-		tss := getSumInstantValues(qtChild, tssCached, tssStart, tssEnd)
+		tss := getSumInstantValues(qtChild, tssCached, tssStart, tssEnd, timestamp)
 		return tss, nil
 	default:
 		qt.Printf("instant rollup optimization isn't implemented for %s()", funcName)
@@ -1441,8 +1441,8 @@ func hasDuplicateSeries(tss []*timeseries) bool {
 	return false
 }
 
-func getMinInstantValues(qt *querytracer.Tracer, tssCached, tssStart, tssEnd []*timeseries) ([]*timeseries, bool) {
-	qt = qt.NewChild("calculate the minimum for instant values across series; cached=%d, start=%d, end=%d", len(tssCached), len(tssStart), len(tssEnd))
+func getMinInstantValues(qt *querytracer.Tracer, tssCached, tssStart, tssEnd []*timeseries, timestamp int64) ([]*timeseries, bool) {
+	qt = qt.NewChild("calculate the minimum for instant values across series; cached=%d, start=%d, end=%d, timestamp=%d", len(tssCached), len(tssStart), len(tssEnd), timestamp)
 	defer qt.Done()
 
 	getMin := func(a, b float64) float64 {
@@ -1451,13 +1451,13 @@ func getMinInstantValues(qt *querytracer.Tracer, tssCached, tssStart, tssEnd []*
 		}
 		return b
 	}
-	tss, ok := getMinMaxInstantValues(tssCached, tssStart, tssEnd, getMin)
+	tss, ok := getMinMaxInstantValues(tssCached, tssStart, tssEnd, timestamp, getMin)
 	qt.Printf("resulting series=%d; ok=%v", len(tss), ok)
 	return tss, ok
 }
 
-func getMaxInstantValues(qt *querytracer.Tracer, tssCached, tssStart, tssEnd []*timeseries) ([]*timeseries, bool) {
-	qt = qt.NewChild("calculate the maximum for instant values across series; cached=%d, start=%d, end=%d", len(tssCached), len(tssStart), len(tssEnd))
+func getMaxInstantValues(qt *querytracer.Tracer, tssCached, tssStart, tssEnd []*timeseries, timestamp int64) ([]*timeseries, bool) {
+	qt = qt.NewChild("calculate the maximum for instant values across series; cached=%d, start=%d, end=%d, timestamp=%d", len(tssCached), len(tssStart), len(tssEnd), timestamp)
 	defer qt.Done()
 
 	getMax := func(a, b float64) float64 {
@@ -1466,12 +1466,12 @@ func getMaxInstantValues(qt *querytracer.Tracer, tssCached, tssStart, tssEnd []*
 		}
 		return b
 	}
-	tss, ok := getMinMaxInstantValues(tssCached, tssStart, tssEnd, getMax)
+	tss, ok := getMinMaxInstantValues(tssCached, tssStart, tssEnd, timestamp, getMax)
 	qt.Printf("resulting series=%d", len(tss))
 	return tss, ok
 }
 
-func getMinMaxInstantValues(tssCached, tssStart, tssEnd []*timeseries, f func(a, b float64) float64) ([]*timeseries, bool) {
+func getMinMaxInstantValues(tssCached, tssStart, tssEnd []*timeseries, timestamp int64, f func(a, b float64) float64) ([]*timeseries, bool) {
 	assertInstantValues(tssCached)
 	assertInstantValues(tssStart)
 	assertInstantValues(tssEnd)
@@ -1522,12 +1522,16 @@ func getMinMaxInstantValues(tssCached, tssStart, tssEnd []*timeseries, f func(a,
 	for _, ts := range m {
 		rvs = append(rvs, ts)
 	}
+
+	setInstantTimestamp(rvs, timestamp)
+
 	return rvs, true
 }
 
-// getSumInstantValues calculates tssCached + tssStart - tssEnd
-func getSumInstantValues(qt *querytracer.Tracer, tssCached, tssStart, tssEnd []*timeseries) []*timeseries {
-	qt = qt.NewChild("calculate the sum for instant values across series; cached=%d, start=%d, end=%d", len(tssCached), len(tssStart), len(tssEnd))
+// getSumInstantValues aggregates tssCached, tssStart, tssEnd time series
+// into a new time series with value = tssCached + tssStart - tssEnd
+func getSumInstantValues(qt *querytracer.Tracer, tssCached, tssStart, tssEnd []*timeseries, timestamp int64) []*timeseries {
+	qt = qt.NewChild("calculate the sum for instant values across series; cached=%d, start=%d, end=%d, timestamp=%d", len(tssCached), len(tssStart), len(tssEnd), timestamp)
 	defer qt.Done()
 
 	assertInstantValues(tssCached)
@@ -1572,10 +1576,19 @@ func getSumInstantValues(qt *querytracer.Tracer, tssCached, tssStart, tssEnd []*
 	for _, ts := range m {
 		rvs = append(rvs, ts)
 	}
+
+	setInstantTimestamp(rvs, timestamp)
+
 	qt.Printf("resulting series=%d", len(rvs))
 	return rvs
 }
 
+func setInstantTimestamp(tss []*timeseries, timestamp int64) {
+	for _, ts := range tss {
+		ts.Timestamps[0] = timestamp
+	}
+}
+
 func assertInstantValues(tss []*timeseries) {
 	for _, ts := range tss {
 		if len(ts.Values) != 1 {
diff --git a/app/vmselect/promql/eval_test.go b/app/vmselect/promql/eval_test.go
index 30a1d9d71d..741ecde618 100644
--- a/app/vmselect/promql/eval_test.go
+++ b/app/vmselect/promql/eval_test.go
@@ -1,6 +1,7 @@
 package promql
 
 import (
+	"reflect"
 	"testing"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/prometheus"
@@ -95,3 +96,77 @@ func TestQueryStats_addSeriesFetched(t *testing.T) {
 		t.Fatalf("expected to get 4; got %d instead", qs.SeriesFetched)
 	}
 }
+
+func TestGetSumInstantValues(t *testing.T) {
+	f := func(cached, start, end []*timeseries, timestamp int64, expectedResult []*timeseries) {
+		t.Helper()
+
+		result := getSumInstantValues(nil, cached, start, end, timestamp)
+		if !reflect.DeepEqual(result, expectedResult) {
+			t.Errorf("unexpected result; got\n%v\nwant\n%v", result, expectedResult)
+		}
+	}
+	ts := func(name string, timestamp int64, value float64) *timeseries {
+		return &timeseries{
+			MetricName: storage.MetricName{
+				MetricGroup: []byte(name),
+			},
+			Timestamps: []int64{timestamp},
+			Values:     []float64{value},
+		}
+	}
+
+	// start - end + cached = 1
+	f(
+		nil,
+		[]*timeseries{ts("foo", 42, 1)},
+		nil,
+		100,
+		[]*timeseries{ts("foo", 100, 1)},
+	)
+
+	// start - end + cached = 0
+	f(
+		nil,
+		[]*timeseries{ts("foo", 100, 1)},
+		[]*timeseries{ts("foo", 10, 1)},
+		100,
+		[]*timeseries{ts("foo", 100, 0)},
+	)
+
+	// start - end + cached = 2
+	f(
+		[]*timeseries{ts("foo", 10, 1)},
+		[]*timeseries{ts("foo", 100, 1)},
+		nil,
+		100,
+		[]*timeseries{ts("foo", 100, 2)},
+	)
+
+	// start - end + cached = 1
+	f(
+		[]*timeseries{ts("foo", 50, 1)},
+		[]*timeseries{ts("foo", 100, 1)},
+		[]*timeseries{ts("foo", 10, 1)},
+		100,
+		[]*timeseries{ts("foo", 100, 1)},
+	)
+
+	// start - end + cached = 0
+	f(
+		[]*timeseries{ts("foo", 50, 1)},
+		nil,
+		[]*timeseries{ts("foo", 10, 1)},
+		100,
+		[]*timeseries{ts("foo", 100, 0)},
+	)
+
+	// start - end + cached = 1
+	f(
+		[]*timeseries{ts("foo", 50, 1)},
+		nil,
+		nil,
+		100,
+		[]*timeseries{ts("foo", 100, 1)},
+	)
+}
diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index f22656dda1..5997fabd40 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -95,6 +95,7 @@ The sandbox cluster installation is running under the constant load generated by
 * BUGFIX: [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html): properly process queries with too big lookbehind window such as `foo[100y]`. Previously, such queries could return empty responses even if `foo` is present in database. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5553).
 * BUGFIX: [MetricsQL](https://docs.victoriametrics.com/MetricsQL.html): properly handle possible negative results caused by float operations precision error in rollup functions like rate() or increase(). See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5571).
 * BUGFIX: `vmselect`: vmsingle/vmselect returns http status 429 (TooManyRequests) instead of 503 (ServiceUnavailable) when max concurrent requests limit is reached.
+* BUGFIX: `vmselect`: set proper timestamps in [instant query](https://docs.victoriametrics.com/keyconcepts/#instant-query) results if the query contains [rollup functions](https://docs.victoriametrics.com/metricsql/#rollup-functions) with lookbehind windows in square brackets exceeding 3 hours. For example, `sum(avg_over_time(up[24h]))`. This bug has been introduced in [v1.95.0](https://docs.victoriametrics.com/changelog_2023/#v1950). See [this](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5659) and [this](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5730) issues.
 
 ## [v1.96.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v1.96.0)