Java Utililty Methods TimeZone

Date extractTimeZone(String strdate, Date thedate)
extract Time Zone

String tzSign = strdate.substring(strdate.length() - 6, strdate.length() - 5);
String tzHour = strdate.substring(strdate.length() - 5, strdate.length() - 3);
String tzMin = strdate.substring(strdate.length() - 2);
if (tzSign.equals("-") || tzSign.equals("+")) {
 int h = Integer.parseInt(tzHour);
 int m = Integer.parseInt(tzMin);
 if (tzSign.equals("+")) {
 h = -1 * h;
...

Date getDateAtTimeZone(Date when, TimeZone from, TimeZone to)
get Date At Time Zone

Calendar result = Calendar.getInstance();
result.setTime(when);
int offset = to.getOffset(when.getTime()) - from.getOffset(when.getTime());
result.add(Calendar.MILLISECOND, offset);
return result.getTime();

Hashtable getDateAttributes(long millisec, TimeZone tz, boolean showNumber)
get Date Attributes

Calendar cal = null;
if (tz == null)
 cal = Calendar.getInstance();
else
 cal = Calendar.getInstance(tz);
cal.setLenient(true);
cal.setTimeInMillis(millisec);
java.util.Date d = cal.getTime();
...

Long getDateBoxValue(TimeZone zone, Date date)
Returns the value for the UTCDateBox for a specified TimeZone and Date .

if (date == null)
 return null;
Calendar cal = GregorianCalendar.getInstance(zone);
cal.setTime(date);
Calendar gmt = GregorianCalendar.getInstance(TimeZone.getTimeZone("GMT"));
gmt.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), cal.get(Calendar.DAY_OF_MONTH));
gmt.set(Calendar.HOUR_OF_DAY, 0);
gmt.set(Calendar.MINUTE, 0);
...

Date getDateValue(TimeZone zone, Long dateBoxValue, Long timeBoxValue)
Returns the Date for the values of the UTCDateBox and UTCTimeBox which were edited in the specified TimeZone .

if (dateBoxValue == null)
 return null;
Calendar gmt = GregorianCalendar.getInstance(TimeZone.getTimeZone("GMT"));
gmt.setTimeInMillis(dateBoxValue.longValue());
Calendar cal = GregorianCalendar.getInstance(zone);
cal.set(gmt.get(Calendar.YEAR), gmt.get(Calendar.MONTH), gmt.get(Calendar.DAY_OF_MONTH));
int hours, minutes, extraMillis;
if (timeBoxValue != null) {
...

Calendar getDateWithoutTimeZone(Date date)
Returns a Calendar without time zone & time

if (date == null) {
 return null;
Calendar cal = getCalendarWithoutTimeZone(date);
cal.clear(Calendar.ZONE_OFFSET);
cal.set(Calendar.HOUR, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
...

double getExcelSerialDayNumber(Date date, Locale locale, TimeZone timeZone)
get Excel Serial Day Number

GregorianCalendar calendar = new GregorianCalendar(timeZone, locale);
calendar.setTime(date);
int year = calendar.get(Calendar.YEAR);
int month = calendar.get(Calendar.MONTH); 
int day = calendar.get(Calendar.DAY_OF_MONTH);
int hour = calendar.get(Calendar.HOUR_OF_DAY);
int min = calendar.get(Calendar.MINUTE);
int sec = calendar.get(Calendar.SECOND);
...

java.util.Date getLocalTime(java.util.TimeZone localTimeZone, java.util.Date timestamp, java.util.TimeZone sourceTimeZone)
get Local Time

if (timestamp != null) {
 if (localTimeZone == null) {
 throw new IllegalArgumentException("localTimeZone cannot be null");
 if (sourceTimeZone == null) {
 throw new IllegalArgumentException("sourceTimeZone cannot be null");
 java.util.Calendar c = java.util.Calendar.getInstance();
...

Date getTimezoneDate(String stateCode)
get Timezone Date

final int GMT8 = 8;
Calendar calendar = Calendar.getInstance();
@SuppressWarnings("deprecation")
Date date = new Date();
date.setHours(date.getHours() + GMT8);
return date;

int getTimeZoneOffset(Date d)
get Time Zone Offset

Calendar c = getCalendar();
c.setTime(d);
return (c.get(Calendar.ZONE_OFFSET) + c.get(Calendar.DST_OFFSET));