diff --git a/coding/indexable/time.go b/coding/indexable/time.go
index b5bdae126..852a551f8 100644
--- a/coding/indexable/time.go
+++ b/coding/indexable/time.go
@@ -18,14 +18,14 @@ import (
 	"time"
 )
 
-var (
-	EarliestTime = EncodeTime(time.Time{})
-)
-
+// EncodeTimeInto writes the provided time into the specified buffer subject
+// to the LevelDB big endian key sort order requirement.
 func EncodeTimeInto(dst []byte, t time.Time) {
 	binary.BigEndian.PutUint64(dst, uint64(t.Unix()))
 }
 
+// EncodeTime converts the provided time into a byte buffer subject to the
+// LevelDB big endian key sort order requirement.
 func EncodeTime(t time.Time) []byte {
 	buffer := make([]byte, 8)
 
@@ -34,6 +34,8 @@ func EncodeTime(t time.Time) []byte {
 	return buffer
 }
 
+// DecodeTime deserializes a big endian byte array into a Unix time in UTC,
+// omitting granularity precision less than a second.
 func DecodeTime(src []byte) time.Time {
-	return time.Unix(int64(binary.BigEndian.Uint64(src)), 0)
+	return time.Unix(int64(binary.BigEndian.Uint64(src)), 0).UTC()
 }
diff --git a/model/metric.go b/model/metric.go
index 6289f9057..223b2ab8e 100644
--- a/model/metric.go
+++ b/model/metric.go
@@ -139,7 +139,7 @@ func (v Values) InsideInterval(t time.Time) (s bool) {
 func NewValuesFromDTO(dto *dto.SampleValueSeries) (v Values) {
 	for _, value := range dto.Value {
 		v = append(v, SamplePair{
-			Timestamp: time.Unix(*value.Timestamp, 0),
+			Timestamp: time.Unix(*value.Timestamp, 0).UTC(),
 			Value:     SampleValue(*value.Value),
 		})
 	}
diff --git a/model/samplekey.go b/model/samplekey.go
index 75f5b365d..ed9be185c 100644
--- a/model/samplekey.go
+++ b/model/samplekey.go
@@ -73,7 +73,7 @@ func NewSampleKeyFromDTO(dto *dto.SampleKey) SampleKey {
 	return SampleKey{
 		Fingerprint:    NewFingerprintFromDTO(dto.Fingerprint),
 		FirstTimestamp: indexable.DecodeTime(dto.Timestamp),
-		LastTimestamp:  time.Unix(*dto.LastTimestamp, 0),
+		LastTimestamp:  time.Unix(*dto.LastTimestamp, 0).UTC(),
 		SampleCount:    *dto.SampleCount,
 	}
 }
diff --git a/model/watermark.go b/model/watermark.go
index e6126bd41..0268c35b4 100644
--- a/model/watermark.go
+++ b/model/watermark.go
@@ -37,7 +37,7 @@ func (w Watermark) ToMetricHighWatermarkDTO() *dto.MetricHighWatermark {
 // dto.MetricHighWatermark object.
 func NewWatermarkFromHighWatermarkDTO(d *dto.MetricHighWatermark) Watermark {
 	return Watermark{
-		time.Unix(*d.Timestamp, 0),
+		time.Unix(*d.Timestamp, 0).UTC(),
 	}
 }
 
diff --git a/web/api/query.go b/web/api/query.go
index 9b3015a51..ac3641bf4 100644
--- a/web/api/query.go
+++ b/web/api/query.go
@@ -84,8 +84,8 @@ func (serv MetricsService) QueryRange(expr string, end int64, duration int64, st
 
 	matrix, err := ast.EvalVectorRange(
 		exprNode.(ast.VectorNode),
-		time.Unix(end-duration, 0),
-		time.Unix(end, 0),
+		time.Unix(end-duration, 0).UTC(),
+		time.Unix(end, 0).UTC(),
 		time.Duration(step)*time.Second)
 	if err != nil {
 		return ast.ErrorToJSON(err)