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TimeUtils.javaAPI DocAndroid 1.5 API5127Wed May 06 22:41:56 BST 2009android.util

TimeUtils

public class TimeUtils extends Object
A class containing utility methods related to time zones.

Fields Summary
private static final String
TAG
Constructors Summary
Methods Summary
public static java.util.TimeZonegetTimeZone(int offset, boolean dst, long when, java.lang.String country)
Tries to return a time zone that would have had the specified offset and DST value at the specified moment in the specified country. Returns null if no suitable zone could be found.


                                          
               
        if (country == null) {
            return null;
        }

        TimeZone best = null;

        Resources r = Resources.getSystem();
        XmlResourceParser parser = r.getXml(com.android.internal.R.xml.time_zones_by_country);
        Date d = new Date(when);

        TimeZone current = TimeZone.getDefault();
        String currentName = current.getID();
        int currentOffset = current.getOffset(when);
        boolean currentDst = current.inDaylightTime(d);

        try {
            XmlUtils.beginDocument(parser, "timezones");

            while (true) {
                XmlUtils.nextElement(parser);

                String element = parser.getName();
                if (element == null || !(element.equals("timezone"))) {
                    break;
                }

                String code = parser.getAttributeValue(null, "code");

                if (country.equals(code)) {
                    if (parser.next() == XmlPullParser.TEXT) {
                        String maybe = parser.getText();

                        // If the current time zone is from the right country
                        // and meets the other known properties, keep it
                        // instead of changing to another one.

                        if (maybe.equals(currentName)) {
                            if (currentOffset == offset && currentDst == dst) {
                                return current;
                            }
                        }

                        // Otherwise, take the first zone from the right
                        // country that has the correct current offset and DST.
                        // (Keep iterating instead of returning in case we
                        // haven't encountered the current time zone yet.)

                        if (best == null) {
                            TimeZone tz = TimeZone.getTimeZone(maybe);

                            if (tz.getOffset(when) == offset &&
                                tz.inDaylightTime(d) == dst) {
                                best = tz;
                            }
                        }
                    }
                }
            }
        } catch (XmlPullParserException e) {
            Log.e(TAG, "Got exception while getting preferred time zone.", e);
        } catch (IOException e) {
            Log.e(TAG, "Got exception while getting preferred time zone.", e);
        } finally {
            parser.close();
        }

        return best;
public static java.lang.StringgetTimeZoneDatabaseVersion()
Returns a String indicating the version of the time zone database currently in use. The format of the string is dependent on the underlying time zone database implementation, but will typically contain the year in which the database was updated plus a letter from a to z indicating changes made within that year.

Time zone database updates should be expected to occur periodically due to political and legal changes that cannot be anticipated in advance. Therefore, when computing the UTC time for a future event, applications should be aware that the results may differ following a time zone database update. This method allows applications to detect that a database change has occurred, and to recalculate any cached times accordingly.

The time zone database may be assumed to change only when the device runtime is restarted. Therefore, it is not necessary to re-query the database version during the lifetime of an activity.

        return ZoneInfoDB.getVersion();