From 8890595f5b3f7ece155478bb494c3b09612422e7 Mon Sep 17 00:00:00 2001
From: "Liu,Linhong" <liulinhong@baidu.com>
Date: Thu, 28 Nov 2019 17:59:27 +0800
Subject: [PATCH 1/2] [SPARK-29486][SQL][FOLLOWUP] Document the reason to add
 days field

---
 .../java/org/apache/spark/unsafe/types/CalendarInterval.java   | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/common/unsafe/src/main/java/org/apache/spark/unsafe/types/CalendarInterval.java b/common/unsafe/src/main/java/org/apache/spark/unsafe/types/CalendarInterval.java
index d2abb36b0727..4826c5db2645 100644
--- a/common/unsafe/src/main/java/org/apache/spark/unsafe/types/CalendarInterval.java
+++ b/common/unsafe/src/main/java/org/apache/spark/unsafe/types/CalendarInterval.java
@@ -34,6 +34,9 @@ public final class CalendarInterval implements Serializable, Comparable<Calendar
   public final int days;
   public final long microseconds;
 
+  // Previous CalendarInterval has 2 fields: months and microseconds. Here we add one more days
+  // fields due to one logical day interval may have different number of microseconds (daylight
+  // saving).
   public CalendarInterval(int months, int days, long microseconds) {
     this.months = months;
     this.days = days;

From 114eb37e50024dc9681f7f0b32a6d11b8cbde34b Mon Sep 17 00:00:00 2001
From: "Liu,Linhong" <liulinhong@baidu.com>
Date: Thu, 28 Nov 2019 19:19:47 +0800
Subject: [PATCH 2/2] change another way to explain

---
 .../org/apache/spark/unsafe/types/CalendarInterval.java    | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/common/unsafe/src/main/java/org/apache/spark/unsafe/types/CalendarInterval.java b/common/unsafe/src/main/java/org/apache/spark/unsafe/types/CalendarInterval.java
index 4826c5db2645..9f0bcd6ad82f 100644
--- a/common/unsafe/src/main/java/org/apache/spark/unsafe/types/CalendarInterval.java
+++ b/common/unsafe/src/main/java/org/apache/spark/unsafe/types/CalendarInterval.java
@@ -34,9 +34,10 @@ public final class CalendarInterval implements Serializable, Comparable<Calendar
   public final int days;
   public final long microseconds;
 
-  // Previous CalendarInterval has 2 fields: months and microseconds. Here we add one more days
-  // fields due to one logical day interval may have different number of microseconds (daylight
-  // saving).
+  // CalendarInterval is represented by months, days and microseconds. Months and days are not
+  // units of time with a constant length (unlike hours, seconds), so they are two separated fields
+  // from microseconds. One month may be equal to 29, 30 or 31 days and one day may be equal to
+  // 23, 24 or 25 hours (daylight saving)
   public CalendarInterval(int months, int days, long microseconds) {
     this.months = months;
     this.days = days;