Bug 13686 - Problems with System.TimeZoneInfo
Summary: Problems with System.TimeZoneInfo
Alias: None
Product: Android
Classification: Xamarin
Component: BCL Class Libraries ()
Version: 4.8.x
Hardware: Macintosh Mac OS
: Highest normal
Target Milestone: 4.8.2 (Android 18)
Assignee: Jonathan Pryor
Depends on:
Reported: 2013-08-01 13:53 UTC by Neal
Modified: 2013-08-23 13:55 UTC (History)
5 users (show)

Is this bug a regression?: ---
Last known good build:

sample app (12.39 KB, application/zip)
2013-08-01 14:00 UTC, Neal

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Description Neal 2013-08-01 13:53:02 UTC

I'm still investigating but it appears with Android 4.3 and/or Mono for Android 4.8.x (I have 4.8.1 beta installed now) that System.TimeZoneInfo is not working.  For example, if I try to return TimeZoneInfo.Local.StandardName it errors out.
Comment 1 Neal 2013-08-01 14:00:43 UTC
Created attachment 4514 [details]
sample app
Comment 2 Neal 2013-08-01 14:00:52 UTC
this is a show stopper for me.  Please fix ASAP.  See sample app attached.
Comment 3 Jonathan Pryor 2013-08-01 14:40:52 UTC
What is the output of:

    adb shell getprop persist.sys.timezone

If it prints nothing, then this is Bug #4902.

What device is this? What stack trace does it generate?
Comment 4 Neal 2013-08-01 14:47:23 UTC
It's a Jelly bean 4.3 emulator, I'll try to get the other info you need now.  I included a sample if you can run it against a 4.3 emulator, I'm using the Mac if that matters.
Comment 5 Neal 2013-08-01 15:10:58 UTC
The message + exception is:

Object reference not set to an instance of an object
  at XamSample.MainActivity+<OnCreate>c__AnonStorey0.<>m__0 (System.Object , System.EventArgs ) [0x0000d] in /Users/Neal/Dev/XamSample/XamSample/MainActivity.cs:35

I don't know how to run adb on a Mac.  If you want to walk me through it reply with info or call me at 323-1223
Comment 6 Jonathan Pryor 2013-08-01 15:18:22 UTC
By default,the Android SDK is installed into:


Thus, please open Terminal.app, then:

    cd $HOME/Library/Developer/Xamarin/android-sdk-mac_x86/platform-tools
    ./adb shell getprop persist.sys.timezone
Comment 7 Neal 2013-08-01 15:26:38 UTC

I ran that command and I get "America/New_York

But I'm not sure what this is for, I do have the emulator running but am I in fact getting the value from the emulator?
Comment 8 Neal 2013-08-01 15:29:08 UTC
I did a ./adb devices and it shows the emulator, it again returned America/New_York

Did you try the sample against Android 4.3 and repro the issue by any chance?
Comment 9 Jonathan Pryor 2013-08-01 15:30:58 UTC
If you don't have a hardware device plugged in, then `adb` will connect to your emulator. If you did have both the emulator running and a device plugged in, you'd get an error asking you to specify a target to connect to.

> Did you try the sample against Android 4.3 and repro the issue by any chance?

Not yet.
Comment 10 Neal 2013-08-01 17:07:31 UTC

I tested against gingerbread (2.3.3 api 10) and it works fine.  It seems to be isolated to Android 4.3 (18)
Comment 11 Neal 2013-08-02 07:59:11 UTC
Please see bugzilla case 7953 as it may be similar and still need to be fixed?
Comment 12 Neal 2013-08-02 09:51:15 UTC
GetSystemTimesZones is also dead.
Comment 14 horizoniosdev 2013-08-02 10:57:11 UTC

- I also see the bug on an Android 4.3 Nexus 4.

- My device correctly returns my timezone with "adb shell getprop persist.sys.timezone"

- You can test for the bug in one line of code in any app:

var offset = TimeZoneInfo.Local.GetUtcOffset(DateTime.Now.AddDays(10))

in the example above, ".Local" will be null

- My deployed app in store is now trashed on 4.3 devices because of this bug (if that helps anybody prioritize)

- This bug affects the popular ServiceStack.Text library which makes use of the TimeZone lookup
Comment 15 Jonathan Pryor 2013-08-02 14:53:40 UTC
Google/Android changed their timezone info file format. It used to consist of the files $ANDROID_ROOT/usr/share/zoneinfo/zoneinfo.dat and $ANDROID_ROOT/usr/share/zoneinfo/zoneinfo.idx.

Now, none of those exist, and instead it's $ANDROID_ROOT/usr/share/zoneinfo/tzdata.

Looks like we need to port: https://android.googlesource.com/platform/libcore/+/master/luni/src/main/java/libcore/util/ZoneInfoDB.java
Comment 16 Jonathan Pryor 2013-08-06 14:47:25 UTC
Mono has Android v4.3 tzdata support as of mono/82a197e4:


Fixed in monodroid/33e5abc7.
Comment 17 Mohit Kheterpal 2013-08-23 13:55:28 UTC
Today we are try to verify this issue with following builds :

XS 4.1.9(build 7)
X.Android 4.8.02054
Mono 3.2.2

When we run the attached sample application in comment 1 on Device(4.3), It deploy successfully without any error and "Hello world click me button appears" and when we click on this button it converts its into "IST" button.

I am not sure about the correct behavior. Please suggest if a miss something to check.