Manual disabled format B

Author: LuciferYang

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/util/DateTimeFormatterHelper.scala

@@ -280,6 +280,7 @@ private object DateTimeFormatterHelper {
   // 2.4, the SimpleDateFormat uses Monday as the first day of week.
   final val weekBasedLetters = Set('Y', 'W', 'w', 'u', 'e', 'c')
   final val unsupportedLetters = Set('A', 'n', 'N', 'p')
+  final val unknownPatternLetters: Set[Char] = Set('B')
   // The quarter fields will also be parsed strangely, e.g. when the pattern contains `yMd` and can
   // be directly resolved then the `q` do check for whether the month is valid, but if the date
   // fields is incomplete, e.g. `yM`, the checking will be bypassed.
@@ -322,6 +323,13 @@ private object DateTimeFormatterHelper {
             (isParsing && unsupportedLettersForParsing.contains(c))) {
             throw new IllegalArgumentException(s"Illegal pattern character: $c")
           }
+          // SPARK-36970: `select date_format('2018-11-17 13:33:33.333', 'B')` failed with Java 8,
+          // but use Java 17 will return `in the afternoon` because 'B' is used to represent
+          // `Pattern letters to output a day period` in Java 17 and manual disabled it here for
+          // compatibility with Java 8 behavior.
+          for (c <- patternPart if unknownPatternLetters.contains(c)) {
+            throw new IllegalArgumentException(s"Unknown pattern letter: $c")
+          }
           for (style <- unsupportedPatternLengths if patternPart.contains(style)) {
             throw new IllegalArgumentException(s"Too many pattern letters: ${style.head}")
           }