How does iphone4 delay sending text messages?

First make sure that iphone4 is jailbroken, and then set it as follows:

1. Open Cydia to search biteSMS and install it;

2. In the SMS content interface, press and hold the SMS content, and select "Forward" in the pop-up menu;

3. The recipient fills in the mobile phone number, clicks the "+"sign on the left side of the input box to pop up the menu, and selects the clock number to set the time;

4. After setting the sending time, click Finish.