#4152 Fix date time formatter always showing Z when it should show actual timezone

Author: stroomdev66

stroom-core-client/src/main/java/stroom/preferences/client/DateTimeFormatter.java

@@ -36,16 +36,14 @@ public String format(final Long ms) {
         }
 
         Use use = Use.UTC;
-        String pattern = "YYYY-MM-DDTHH:mm:ss.SSS[Z]";
+        String pattern = "YYYY-MM-DD[T]HH:mm:ss.SSSZ";
         int offsetMinutes = 0;
         String zoneId = "UTC";
 
         final UserPreferences userPreferences = userPreferencesManager.getCurrentUserPreferences();
         if (userPreferences != null) {
-            if (userPreferences.getDateTimePattern() != null
-                    && userPreferences.getDateTimePattern().trim().length() > 0) {
-                pattern = userPreferences.getDateTimePattern();
-                pattern = convertJavaDateTimePattern(pattern);
+            if (userPreferences.getDateTimePattern() != null &&
+                    userPreferences.getDateTimePattern().trim().length() > 0) {
 
                 final TimeZone timeZone = userPreferences.getTimeZone();
                 if (timeZone != null) {
@@ -62,9 +60,20 @@ public String format(final Long ms) {
 
                     zoneId = timeZone.getId();
                 }
+
+                pattern = userPreferences.getDateTimePattern();
+                pattern = convertJavaDateTimePattern(pattern);
             }
         }
 
+        // If UTC then just display the `Z` suffix.
+        if (Use.UTC.equals(use)) {
+            pattern = pattern.replaceAll("Z", "[Z]");
+        }
+        // Ensure we haven't doubled up square brackets.
+        pattern = pattern.replaceAll("\\[+", "[");
+        pattern = pattern.replaceAll("]+", "]");
+
         return nativeToDateString(ms, use.getDisplayValue(), pattern, zoneId, offsetMinutes);
     }
 
@@ -73,7 +82,8 @@ String convertJavaDateTimePattern(final String pattern) {
         converted = converted.replace('y', 'Y');
         converted = converted.replace('d', 'D');
         converted = converted.replaceAll("'", "");
-        converted = converted.replaceAll("SSSXX", "SSS[Z]");
+        converted = converted.replaceAll("SSSXX", "SSSZ");
+        converted = converted.replaceAll("T", "[T]");
         converted = converted.replaceAll("xxx", "Z");
         converted = converted.replaceAll("xx", "z");
         converted = converted.replaceAll("VV", "ZZ");

unreleased_changes/20240308_095510_520__4152.md

@@ -0,0 +1,24 @@
+* Issue **#4152** : Fix date time formatter always showing `Z` when it should show actual timezone.
+
+
+```sh
+# ********************************************************************************
+# Issue title: When displaying date/times as non UTC, Stroom incorrectly showing `Z` suffix as opposed to actual offset
+# Issue link:  https://github.com/gchq/stroom/issues/4152
+# ********************************************************************************
+
+# ONLY the top line will be included as a change entry in the CHANGELOG.
+# The entry should be in GitHub flavour markdown and should be written on a SINGLE
+# line with no hard breaks. You can have multiple change files for a single GitHub issue.
+# The  entry should be written in the imperative mood, i.e. 'Fix nasty bug' rather than
+# 'Fixed nasty bug'.
+#
+# Examples of acceptable entries are:
+#
+#
+# * Issue **123** : Fix bug with an associated GitHub issue in this repository
+#
+# * Issue **namespace/other-repo#456** : Fix bug with an associated GitHub issue in another repository
+#
+# * Fix bug with no associated GitHub issue.
+```