How long does it take to get a text message and disappear normally?

I don't understand your question. How can I receive a text message when my phone is turned off?

If someone sends you a short message when your phone is turned off, although you can't receive the short message immediately, the telecom server will still keep your short message for a period of time (usually 48 hours), and you can receive other people's short messages when your phone is turned on. If a mobile phone receives a short message, but fails to check it in time, the message will not disappear, but will remain.