Android Daylight savings time设置问题

Android中对 Daylight savings time的处理是根据时区来处理的。

framework/com/android/server/AlarmManagerService.java有说明。

 TimeZone zone = TimeZone.getTimeZone(tz);

261        // Prevent reentrant calls from stepping on each other when writing

262        // the time zone property

263        boolean timeZoneWasChanged = false;

264        synchronized (this) {

265            String current = SystemProperties.get(TIMEZONE_PROPERTY);

266            if (current == null || !current.equals(zone.getID())) {

267                if (localLOGV) Slog.v(TAG, "timezone changed: " + current + ", new=" + zone.getID());

268                timeZoneWasChanged = true;

269                SystemProperties.set(TIMEZONE_PROPERTY, zone.getID());

270            }

271             

272            // Update the kernel timezone information

273            // Kernel tracks time offsets as 'minutes west of GMT'

274            int gmtOffset = zone.getRawOffset();

275            if (zone.inDaylightTime(new Date(System.currentTimeMillis()))) {

276                gmtOffset += zone.getDSTSavings();

277            }

278            setKernelTimezone(mDescriptor, -(gmtOffset / 60000));

279        }

280 

281        TimeZone.setDefault(null);