From 8902cf2a7388eb18612dcefa6fa2e56ebfd22681 Mon Sep 17 00:00:00 2001
From: Eric Scharff <scharff@sharedmind.(none)>
Date: Mon, 22 Oct 2007 12:03:15 -0600
Subject: [PATCH 1/2] Added a working implementation of calendar that fills in
 the important fields (year, month, day, hour, minute, second) for the
 Gregorian calendar. Specifically, it fills in YEAR, MONTH, DAY_OF_MONTH,
 HOUR_OF_DAY, MINUTE, and SECOND.

---
 classpath/java/util/Calendar.java | 46 +++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/classpath/java/util/Calendar.java b/classpath/java/util/Calendar.java
index 640b7a237a..5989c9451b 100644
--- a/classpath/java/util/Calendar.java
+++ b/classpath/java/util/Calendar.java
@@ -59,11 +59,57 @@ public abstract class Calendar {
   public abstract int getActualMaximum(int field);
 
   private static class MyCalendar extends Calendar {
+    private static final long MILLIS_PER_DAY = 86400000;
+    private static final int MILLIS_PER_HOUR = 3600000;
+    private static final int MILLIS_PER_MINUTE = 60000;
+    private static final int MILLIS_PER_SECOND = 1000;
+
+    private static final int EPOCH_YEAR = 1970;
+    private static final int[][] DAYS_IN_MONTH = new int[][] {
+      { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
+      { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
+    };
+
     public MyCalendar(long time) {
       this.time = time;
       this.isTimeSet = true;
+      parseIntoFields(time);
     }
 
+    private static boolean isLeapYear(int year) {
+      return (year%4 == 0) && (year%100 != 0) || (year%400 == 0);
+    }
+    
+    private static int daysInYear(int year) {
+      return isLeapYear(year) ? 366 : 365;
+    }
+    
+    private void parseIntoFields(long timeInMillis) {
+      long days = timeInMillis / MILLIS_PER_DAY;
+      int year = EPOCH_YEAR;
+      while (days >= daysInYear(year)) {
+        days -= daysInYear(year++);
+      }
+      int month=0;
+      int leapIndex = isLeapYear(year) ? 1 : 0;
+      while (days >= DAYS_IN_MONTH[leapIndex][month]) {
+        days -= DAYS_IN_MONTH[leapIndex][month++];
+      }
+      days++;
+      int remainder = (int)(timeInMillis % MILLIS_PER_DAY);
+      int hour = remainder / MILLIS_PER_HOUR;
+      remainder = remainder % MILLIS_PER_HOUR;
+      int minute = remainder / MILLIS_PER_MINUTE;
+      remainder = remainder / MILLIS_PER_MINUTE;
+      int second = remainder / MILLIS_PER_SECOND;
+      fields[YEAR] = year;
+      fields[MONTH] = month;
+      fields[DAY_OF_MONTH] = (int)days;
+      fields[HOUR_OF_DAY] = hour;
+      fields[MINUTE] = minute;
+      fields[SECOND] = second;
+    }
+    
     public void roll(int field, boolean up) {
       // todo
     }

From 7eb08c5fc41e2c76a8c454c04d78cc30086e29ed Mon Sep 17 00:00:00 2001
From: Eric Scharff <scharff@sharedmind.(none)>
Date: Mon, 22 Oct 2007 12:23:56 -0600
Subject: [PATCH 2/2] If a Calendar changes values, update the (cached) fields.

---
 classpath/java/util/Calendar.java | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/classpath/java/util/Calendar.java b/classpath/java/util/Calendar.java
index 5989c9451b..c479cc49fc 100644
--- a/classpath/java/util/Calendar.java
+++ b/classpath/java/util/Calendar.java
@@ -76,6 +76,11 @@ public abstract class Calendar {
       parseIntoFields(time);
     }
 
+    public void setTime(Date date) {
+      super.setTime(date);
+      parseIntoFields(this.time);
+    }
+
     private static boolean isLeapYear(int year) {
       return (year%4 == 0) && (year%100 != 0) || (year%400 == 0);
     }