About i message
I received a sms in i message when my phone is turn off and when i turned it on the timestamp of that message is same time as, the time i turned on my phone, so how can i know exact time of msg that they were sent.
Given the circumstances that you have listed in your post, the only way that you can get the exact time when the messages were sent is by asking the sender of the messages. I am afraid that there is no other way.
Axel F.