It was my mistake, I didn’t read Milot’s post properly. I thought he had asked to close it, but now I see that he had mentioned just to mark it as solved.

QtK wrote:

If the thread is closed now. We won’t find whether the issue was with certificate date or the date on the device was wrong. May be we should wait till David Chang confirms what the issue was. And then the admins can close this thread.

Thank you guys. Just make it solved. Sorry for the late reply. I confirm that it is due to my device set wrong date ( 2011, Nov. xxx).

This is one of the most frequently faced issue.