Why do I need root?

Setting device system time requires root permissions. It's not a limitation of ClockSync, but a restriction of Android platform security. Applications run on Android with user access level which doesn't allow some operations including changing the system time. Such restriction is not unique to Android, the same is valid for iPhone OS and any Linux. At the moment there is no known way to set system time automatically without root on Android and there is no other third-party application which does it without root.

Rest assured I'll provide an update as soon as such a way is discovered in the future. You can still use ClockSync as your reference time source to synchronize time on your wall clock or wristwatch. I also plan to provide a manual assisted way to set Android system time (ClockSync will open system time settings for you and will provide the instructions what time should be set and alert when to press Set for the best possible precision).

What can I do?

Good news is that most Android devices can be rooted. Please note that rooting will usually void your warranty. Rooting method would depend on the particular device model and ROM. Google is your friend here, it should be pretty easy to find the instructions to root you model (search for: MODEL NAME root). If you don't want or can't get root working on your device, then you will not be able to set system time with ClockSync, sorry.

You can also vote for the Android feature request: Issue 4581: Allow user apps to set the system time.

I have root, still doesn't work

Some devices have su binary which allows to perform commands with different user permissions from the adb shell or terminal. However, it will not necessarily run with the superuser permissions (UID=0) and it also doesn't allow Android applications to use root directly. Check that you have both su binary in /system/xbin or /system/bin and also Superuser.apk (Superuser Permissions application). I strongly recommend using Superuser 2.1 or later by ChainsDD. Please don't hesitate to contact me if you need help.

Market rating notes

Several users have put low ratings in Market because ClockSync was not able to change time on their devices without or with incorrectly working root. I hope for your understanding that it's not a problem of ClockSync and not because the developer was too dumb or lazy to find another way to set system clock. I've put a lot of time and efforts to make ClockSync the best one available in Android Market, free and without ads. I don't think that it deserves 1 star rating. I'm always ready to help with the possible problems for free, because I do care. Please mail me before setting low rating and uninstalling. ClockSync has been tested and is known to work correctly on many devices including Motorola Droid/Milestone, Google Nexus One, HTC Hero, HTC Magic, HTC Legend, HTD Desire, HTC EVO 4G, etc.

Froyo notes

Android 2.2 has introduced the new permission: android.permission.SET_TIME. Unfortunately, it can be used only by system applications signed with the platform key. Third-party apps will not get this permission granted, therefore you still need to have root to set system time even on Froyo. I really hope that security subsystem will change in the future Android versions and system will be able to show you additional warnings before granting possibly dangerous permissions.