[SPARK-19817][SQL] Make it clear that `timeZone` option is a general option in DataFrameReader/Writer.

## What changes were proposed in this pull request?

As timezone setting can also affect partition values, it works for all formats, we should make it clear.

## How was this patch tested?

Existing tests.

Author: Takuya UESHIN <ueshin@databricks.com>

Closes #17281 from ueshin/issues/SPARK-19817.

4 files changed, 13 insertions, 6 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala
index e3631b0c07..b862deaf36 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/catalog/interface.scala
@@ -113,7 +113,8 @@ case class CatalogTablePartition(
    */
   def toRow(partitionSchema: StructType, defaultTimeZondId: String): InternalRow = {
     val caseInsensitiveProperties = CaseInsensitiveMap(storage.properties)
-    val timeZoneId = caseInsensitiveProperties.getOrElse("timeZone", defaultTimeZondId)
+    val timeZoneId = caseInsensitiveProperties.getOrElse(
+      DateTimeUtils.TIMEZONE_OPTION, defaultTimeZondId)
     InternalRow.fromSeq(partitionSchema.map { field =>
       Cast(Literal(spec(field.name)), field.dataType, Option(timeZoneId)).eval()
     })
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/json/JSONOptions.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/json/JSONOptions.scala
index 5a91f9c193..5f222ec602 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/json/JSONOptions.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/json/JSONOptions.scala
@@ -23,7 +23,7 @@ import com.fasterxml.jackson.core.{JsonFactory, JsonParser}
 import org.apache.commons.lang3.time.FastDateFormat
 
 import org.apache.spark.internal.Logging
-import org.apache.spark.sql.catalyst.util.{CaseInsensitiveMap, CompressionCodecs, ParseModes}
+import org.apache.spark.sql.catalyst.util._
 
 /**
  * Options for parsing JSON data into Spark SQL rows.
@@ -69,7 +69,8 @@ private[sql] class JSONOptions(
   val columnNameOfCorruptRecord =
     parameters.getOrElse("columnNameOfCorruptRecord", defaultColumnNameOfCorruptRecord)
 
-  val timeZone: TimeZone = TimeZone.getTimeZone(parameters.getOrElse("timeZone", defaultTimeZoneId))
+  val timeZone: TimeZone = TimeZone.getTimeZone(
+    parameters.getOrElse(DateTimeUtils.TIMEZONE_OPTION, defaultTimeZoneId))
 
   // Uses `FastDateFormat` which can be direct replacement for `SimpleDateFormat` and thread-safe.
   val dateFormat: FastDateFormat =
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/util/DateTimeUtils.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/util/DateTimeUtils.scala
index 9e1de0fd2f..9b94c1e2b4 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/util/DateTimeUtils.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/util/DateTimeUtils.scala
@@ -60,6 +60,8 @@ object DateTimeUtils {
   final val TimeZoneGMT = TimeZone.getTimeZone("GMT")
   final val MonthOf31Days = Set(1, 3, 5, 7, 8, 10, 12)
 
+  val TIMEZONE_OPTION = "timeZone"
+
   def defaultTimeZone(): TimeZone = TimeZone.getDefault()
 
   // Reuse the Calendar object in each thread as it is expensive to create in each method call.
diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/JsonExpressionsSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/JsonExpressionsSuite.scala
index e3584909dd..19d0c8eb92 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/JsonExpressionsSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/expressions/JsonExpressionsSuite.scala
@@ -471,7 +471,8 @@ class JsonExpressionsSuite extends SparkFunSuite with ExpressionEvalHelper {
       checkEvaluation(
         JsonToStruct(
           schema,
-          Map("timestampFormat" -> "yyyy-MM-dd'T'HH:mm:ss", "timeZone" -> tz.getID),
+          Map("timestampFormat" -> "yyyy-MM-dd'T'HH:mm:ss",
+            DateTimeUtils.TIMEZONE_OPTION -> tz.getID),
           Literal(jsonData2),
           gmtId),
         InternalRow(c.getTimeInMillis * 1000L)
@@ -523,14 +524,16 @@ class JsonExpressionsSuite extends SparkFunSuite with ExpressionEvalHelper {
 
     checkEvaluation(
       StructToJson(
-        Map("timestampFormat" -> "yyyy-MM-dd'T'HH:mm:ss", "timeZone" -> gmtId.get),
+        Map("timestampFormat" -> "yyyy-MM-dd'T'HH:mm:ss",
+          DateTimeUtils.TIMEZONE_OPTION -> gmtId.get),
         struct,
         gmtId),
       """{"t":"2016-01-01T00:00:00"}"""
     )
     checkEvaluation(
       StructToJson(
-        Map("timestampFormat" -> "yyyy-MM-dd'T'HH:mm:ss", "timeZone" -> "PST"),
+        Map("timestampFormat" -> "yyyy-MM-dd'T'HH:mm:ss",
+          DateTimeUtils.TIMEZONE_OPTION -> "PST"),
         struct,
         gmtId),
       """{"t":"2015-12-31T16:00:00"}"""