diff --git a/common.go b/common.go
index f1400db..f66c19d 100644
--- a/common.go
+++ b/common.go
@@ -2,7 +2,6 @@ package keystore
 
 import (
 	"encoding/binary"
-	"time"
 )
 
 const (
@@ -33,11 +32,3 @@ func zeroing(buf []byte) {
 		buf[i] = 0
 	}
 }
-
-func millisecondsToTime(ms int64) time.Time {
-	return time.Unix(0, ms*int64(time.Millisecond))
-}
-
-func timeToMilliseconds(t time.Time) int64 {
-	return t.UnixNano() / int64(time.Millisecond)
-}
diff --git a/decoder.go b/decoder.go
index 159c3f8..8047ca7 100644
--- a/decoder.go
+++ b/decoder.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"hash"
 	"io"
+	"time"
 )
 
 const defaultCertificateType = "X509"
@@ -127,7 +128,7 @@ func (d decoder) readPrivateKeyEntry(version uint32) (PrivateKeyEntry, error) {
 		chain = append(chain, cert)
 	}
 
-	creationDateTime := millisecondsToTime(int64(creationTimeStamp))
+	creationDateTime := time.UnixMilli(int64(creationTimeStamp))
 	privateKeyEntry := PrivateKeyEntry{
 		encryptedPrivateKey: encryptedPrivateKey,
 		CreationTime:        creationDateTime,
@@ -148,7 +149,7 @@ func (d decoder) readTrustedCertificateEntry(version uint32) (TrustedCertificate
 		return TrustedCertificateEntry{}, fmt.Errorf("read certificate: %w", err)
 	}
 
-	creationDateTime := millisecondsToTime(int64(creationTimeStamp))
+	creationDateTime := time.UnixMilli(int64(creationTimeStamp))
 	trustedCertificateEntry := TrustedCertificateEntry{
 		CreationTime: creationDateTime,
 		Certificate:  certificate,
diff --git a/encoder.go b/encoder.go
index 5f03bc2..31a7c3a 100644
--- a/encoder.go
+++ b/encoder.go
@@ -95,7 +95,7 @@ func (e encoder) writePrivateKeyEntry(alias string, pke PrivateKeyEntry) error {
 		return fmt.Errorf("write alias: %w", err)
 	}
 
-	if err := e.writeUint64(uint64(timeToMilliseconds(pke.CreationTime))); err != nil {
+	if err := e.writeUint64(uint64(pke.CreationTime.UnixMilli())); err != nil {
 		return fmt.Errorf("write creation timestamp: %w", err)
 	}
 
@@ -140,7 +140,7 @@ func (e encoder) writeTrustedCertificateEntry(alias string, tce TrustedCertifica
 		return fmt.Errorf("write alias: %w", err)
 	}
 
-	if err := e.writeUint64(uint64(timeToMilliseconds(tce.CreationTime))); err != nil {
+	if err := e.writeUint64(uint64(tce.CreationTime.UnixMilli())); err != nil {
 		return fmt.Errorf("write creation timestamp: %w", err)
 	}