TimeBasic is a plugin I created because I basically had no internet and I was bored and I just decided to release it afterwards. It has four commands and it's very simple to use. You don't need to configure anything. Permission or OP works.
Commands and permissions
/time - timebasic.time - sets the time for the player, a lot of options here.
/adtime - timebasic.adtime - sets the time for everyone in the world, a lot of options here too.
/weather - timebasic.weather - sets the weather for the player, a few options here.
/adweather - timebasic.adweather - sets the weather for the world, a few options here as well.
Performing any of these commands with no argument will give you a list of arguments you can use.
There is none as it's not needed.
Source and development
If you want me to make any changes or add something, feel free to let me know and I will.