What is the time when the text message is received? Is it an active mobile phone, a passive mobile phone, or a communication company?

The communication company’s requirement shall prevail. For example, if you send it to an individual now, what if he turns off his phone now? Then he can't receive it now. He will receive it when he turns on his phone. But the time he receives it is definitely the time you sent it, not the time he turned his phone on

Also, if the network is not Okay, it’s the same