Handle hour part extraction in different timezones

Author: alex-kulakov

Orm/Xtensive.Orm.Tests.Sql/PostgreSql/InfinityAliasTest.cs

@@ -469,10 +469,14 @@ private void TestMinDateTimeOffsetSelectDatePart(bool isOn)
         DateTimeOffset.MinValue.Day,
         isOn);
 
-      // timezone for DateTimeOffset.MinValue value in postgre is set to 04:02:33, at least when instance is in UTC+5 timezone
+      var serverSideHours = (localTimezone > TimeSpan.Zero)
+        ? localTimezone.Hours  // positive zone
+        : (localTimezone < TimeSpan.Zero)
+          ? 23 + localTimezone.Hours // negative zone
+          : localTimezone.Hours; // UTC
       TestDateTimeOffsetPartExtraction(DateTimeOffsetMinValueTable, SqlDateTimeOffsetPart.Hour,
-        localTimezone.Hours,
-        localTimezone.Hours,
+        serverSideHours,
+        serverSideHours,
         isOn);
       TestDateTimeOffsetPartExtraction(DateTimeOffsetMinValueTable, SqlDateTimeOffsetPart.Minute,
         DateTimeOffset.MinValue.Minute,

Orm/Xtensive.Orm.Tests/Linq/DateTimeAndDateTimeOffset/DateTimeOffset/PartsExtractionTest.cs

@@ -176,10 +176,10 @@ public void ExtractHourMinValueTest()
 
       ExecuteInsideSession((s) => {
         var serverSideHours = (localTimezone > TimeSpan.Zero)
-        ? localTimezone.Hours - 1  // positive zone
-        : (localTimezone < TimeSpan.Zero)
-          ? 23 + localTimezone.Hours // negative zone
-          : 23; // UTC
+          ? localTimezone.Hours  // positive zone
+          : (localTimezone < TimeSpan.Zero)
+            ? 23 + localTimezone.Hours // negative zone
+            : localTimezone.Hours; // UTC
         RunTest<MinMaxDateTimeOffsetEntity>(s, c => c.MinValue.Hour == serverSideHours);
         RunWrongTest<MinMaxDateTimeOffsetEntity>(s, c => c.MinValue.Hour == DateTimeOffset.MinValue.AddHours(1).Hour);
       });
@@ -192,10 +192,10 @@ public void ExtractHourMaxValueTest()
 
       ExecuteInsideSession((s) => {
         var serverSideHours = (localTimezone > TimeSpan.Zero)
-        ? localTimezone.Hours - 1  // positive zone
-        : (localTimezone < TimeSpan.Zero)
-          ? 23 + localTimezone.Hours // negative zone
-          : 23; // UTC
+          ? localTimezone.Hours - 1  // positive zone
+          : (localTimezone < TimeSpan.Zero)
+            ? 23 + localTimezone.Hours // negative zone
+            : 23; // UTC
         RunTest<MinMaxDateTimeOffsetEntity>(s, c => c.MaxValue.Hour == serverSideHours);
         RunWrongTest<MinMaxDateTimeOffsetEntity>(s, c => c.MaxValue.Hour == DateTimeOffset.MaxValue.AddHours(-1).Hour);
       });