One of the features that I am amazed with on my Samsung S4 is its ability to set timer with Wi-Fi. Using this application helps a lot because all we have to do is to set it up and it will manage itself.
Personally, I am not mindful of turning on and off its Wi-Fi regularly because I always forget to it when I leave the house or the office. By experience we are all aware that having Wi-Fi on eats a lot of battery life because the device is constantly looking for a connection it can use for Wi-Fi. Imagine how much energy you can save if you will shut it off when there is really no available signal.
To use Wi-Fi timer, go to Settings, tap the Wi-Fi menu option under Connections Tab. press the Wi-Fi icon. Now you are showing the different available connections in your location. Then press the lower left button of your phone (this is on the left side of the Home Button of your phone) and you will see the Advanced Settings. Scan the list and you will see the option that says Wi-Fi Timer.