moparisthebest/poi
1
0
Fork 0
Code Issues Pull Requests Releases 1 Wiki Activity

Applied patch 27574

Browse Source 
When setting a cell's value to the date 2004-03-28 08:00 it is presented as
07:00 in Excel. This only happens on the days when DST starts or ends.


git-svn-id: https://svn.apache.org/repos/asf/jakarta/poi/branches/REL_2_BRANCH@353576 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Glen Stampoultzis 2004-08-04 00:43:47 +00:00
parent 2943c5a8e5
commit 95f5211037
2 changed files with 156 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
src/java/org/apache/poi/hssf/usermodel/HSSFDateUtil.java
View File

@ -33,6 +33,7 @@ import java.util.GregorianCalendar;
* @author Michael Harhen
* @author Glen Stampoultzis (glens at apache.org)
* @author Dan Sherman (dsherman at isisph.com)
* @author Hack Kampbjorn (hak at 2mba.dk)
*/
public class HSSFDateUtil
@ -68,9 +69,19 @@ public class HSSFDateUtil
}
else
{
// Because of daylight time saving we cannot use
// date.getTime() - calStart.getTimeInMillis()
// as the difference in milliseconds between 00:00 and 04:00
// can be 3, 4 or 5 hours but Excel expects it to always
// be 4 hours.
// E.g. 2004-03-28 04:00 CEST - 2004-03-28 00:00 CET is 3 hours
// and 2004-10-31 04:00 CET - 2004-10-31 00:00 CEST is 5 hours
double fraction = (((calStart.get(Calendar.HOUR_OF_DAY) * 60
+ calStart.get(Calendar.MINUTE)
) * 60 + calStart.get(Calendar.SECOND)
) * 1000 + calStart.get(Calendar.MILLISECOND)
) / ( double ) DAY_MILLISECONDS;
calStart = dayStart(calStart);
double fraction = (date.getTime() - calStart.getTime().getTime())
/ ( double ) DAY_MILLISECONDS;
return fraction + ( double ) absoluteDay(calStart)
- CAL_1900_ABSOLUTE;
@ -96,10 +107,20 @@ public class HSSFDateUtil
* Given an Excel date with either 1900 or 1904 date windowing,
* converts it to a java.util.Date.
*
* NOTE: If the default <code>TimeZone</code> in Java uses Daylight
* Saving Time then the conversion back to an Excel date may not give
* the same value, that is the comparison
* <CODE>excelDate == getExcelDate(getJavaDate(excelDate,false))</CODE>
* is not always true. For example if default timezone is
* <code>Europe/Copenhagen</code>, on 2004-03-28 the minute after
* 01:59 CET is 03:00 CEST, if the excel date represents a time between
* 02:00 and 03:00 then it is converted to past 03:00 summer time
*
* @param date The Excel date.
* @param use1904windowing true if date uses 1904 windowing,
* or false if using 1900 date windowing.
* @return Java representation of the date, or null if date is not a valid Excel date
* @see java.util.TimeZone
*/
public static Date getJavaDate(double date, boolean use1904windowing) {
if (isValidExcelDate(date)) {

110
src/testcases/org/apache/poi/hssf/usermodel/TestHSSFDateUtil.java
View File

@ -21,7 +21,9 @@ package org.apache.poi.hssf.usermodel;
import junit.framework.TestCase;
import java.util.Date;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.TimeZone;
/**
* Class TestHSSFDateUtil
@ -29,6 +31,7 @@ import java.util.GregorianCalendar;
*
* @author
* @author Dan Sherman (dsherman at isisph.com)
* @author Hack Kampbjorn (hak at 2mba.dk)
* @version %I%, %G%
*/
@ -78,4 +81,111 @@ public class TestHSSFDateUtil
dateIf1904.getTime(),
HSSFDateUtil.getJavaDate(excelDate,true).getTime());
}
/**
* Checks the conversion of a java.util.date to Excel on a day when
* Daylight Saving Time starts.
*/
public void testExcelConversionOnDSTStart() {
TimeZone cet = TimeZone.getTimeZone("Europe/Copenhagen");
TimeZone.setDefault(cet);
Calendar cal = new GregorianCalendar(2004, Calendar.MARCH, 28);
for (int hour = 0; hour < 24; hour++) {
// Skip 02:00 CET as that is the Daylight change time
// and Java converts it automatically to 03:00 CEST
if (hour == 2) {
continue;
}
cal.set(Calendar.HOUR_OF_DAY, hour);
Date javaDate = cal.getTime();
double excelDate = HSSFDateUtil.getExcelDate(javaDate);
double difference = excelDate - Math.floor(excelDate);
int differenceInHours = (int) (difference * 24 * 60 + 0.5) / 60;
assertEquals("Checking " + hour + " hour on Daylight Saving Time start date",
hour,
differenceInHours);
assertEquals("Checking " + hour + " hour on Daylight Saving Time start date",
javaDate.getTime(),
HSSFDateUtil.getJavaDate(excelDate).getTime());
}
}
/**
* Checks the conversion of an Excel date to a java.util.date on a day when
* Daylight Saving Time starts.
*/
public void testJavaConversionOnDSTStart() {
TimeZone cet = TimeZone.getTimeZone("Europe/Copenhagen");
TimeZone.setDefault(cet);
Calendar cal = new GregorianCalendar(2004, Calendar.MARCH, 28);
double excelDate = HSSFDateUtil.getExcelDate(cal.getTime());
double oneHour = 1.0 / 24;
double oneMinute = oneHour / 60;
for (int hour = 0; hour < 24; hour++, excelDate += oneHour) {
// Skip 02:00 CET as that is the Daylight change time
// and Java converts it automatically to 03:00 CEST
if (hour == 2) {
continue;
}
cal.set(Calendar.HOUR_OF_DAY, hour);
Date javaDate = HSSFDateUtil.getJavaDate(excelDate);
assertEquals("Checking " + hour + " hours on Daylight Saving Time start date",
excelDate,
HSSFDateUtil.getExcelDate(javaDate), oneMinute);
}
}
/**
* Checks the conversion of a java.util.Date to Excel on a day when
* Daylight Saving Time ends.
*/
public void testExcelConversionOnDSTEnd() {
TimeZone cet = TimeZone.getTimeZone("Europe/Copenhagen");
TimeZone.setDefault(cet);
Calendar cal = new GregorianCalendar(2004, Calendar.OCTOBER, 31);
for (int hour = 0; hour < 24; hour++) {
cal.set(Calendar.HOUR_OF_DAY, hour);
Date javaDate = cal.getTime();
double excelDate = HSSFDateUtil.getExcelDate(javaDate);
double difference = excelDate - Math.floor(excelDate);
int differenceInHours = (int) (difference * 24 * 60 + 0.5) / 60;
assertEquals("Checking " + hour + " hour on Daylight Saving Time end date",
hour,
differenceInHours);
assertEquals("Checking " + hour + " hour on Daylight Saving Time start date",
javaDate.getTime(),
HSSFDateUtil.getJavaDate(excelDate).getTime());
}
}
/**
* Checks the conversion of an Excel date to java.util.Date on a day when
* Daylight Saving Time ends.
*/
public void testJavaConversionOnDSTEnd() {
TimeZone cet = TimeZone.getTimeZone("Europe/Copenhagen");
TimeZone.setDefault(cet);
Calendar cal = new GregorianCalendar(2004, Calendar.OCTOBER, 31);
double excelDate = HSSFDateUtil.getExcelDate(cal.getTime());
double oneHour = 1.0 / 24;
double oneMinute = oneHour / 60;
for (int hour = 0; hour < 24; hour++, excelDate += oneHour) {
cal.set(Calendar.HOUR_OF_DAY, hour);
Date javaDate = HSSFDateUtil.getJavaDate(excelDate);
assertEquals("Checking " + hour + " hours on Daylight Saving Time start date",
excelDate,
HSSFDateUtil.getExcelDate(javaDate), oneMinute);
}
}
public static void main(String [] args) {
System.out
.println("Testing org.apache.poi.hssf.usermodel.TestHSSFDateUtil");
junit.textui.TestRunner.run(TestHSSFDateUtil.class);
}
}