improve performance of time zone lookup

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1898125 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/poi/src/main/java/org/apache/poi/ss/usermodel/DateUtil.java b/poi/src/main/java/org/apache/poi/ss/usermodel/DateUtil.java
index 7a50951ac7eb6daba7a14ec042c75ffbe25bcfb4..154127a50c66586d5fc63153e8697250e527cbbf 100644 (file)
--- a/poi/src/main/java/org/apache/poi/ss/usermodel/DateUtil.java
+++ b/poi/src/main/java/org/apache/poi/ss/usermodel/DateUtil.java
@@ -93,7 +93,7 @@ public class DateUtil {
      */
     public static LocalDateTime toLocalDateTime(Date date) {
         return date.toInstant()
-                .atZone(TimeZone.getTimeZone(ZoneOffset.UTC).toZoneId()) // java.util.Date uses UTC
+                .atZone(LocaleUtil.TIMEZONE_UTC.toZoneId()) // java.util.Date uses UTC
                 .toLocalDateTime();
     }
 
@@ -104,7 +104,7 @@ public class DateUtil {
      */
     public static LocalDateTime toLocalDateTime(Calendar date) {
         return date.toInstant()
-                .atZone(TimeZone.getTimeZone(ZoneOffset.UTC).toZoneId()) // java.util.Date uses UTC
+                .atZone(LocaleUtil.TIMEZONE_UTC.toZoneId()) // java.util.Date uses UTC
                 .toLocalDateTime();
     }