tzselect的作用是什么？

heavensun

请问tzselect到底有什么用？
我想改变系统时区，用tzselect命令后，选择了我想要的时区，最后出现这么两句“You can make this change permanent for yourself by appending the line
TZ='Asia/Shanghai'; export TZ to the file '.profile' in your home directory; then log out and log in again.

Here is that TZ value again, this time on standard output so that you can use the /usr/bin/tzselect command in shell scripts:
Asia/Shanghai”不知道怎么运用。
大家知道的话，请告诉我~~先谢谢了！