Parts you'll need: an ESP8266 ESP-12E NodeMCU Arduino, I used the ch340g a 7 segment 8 digit LCD display, 0.56 inch a TMP36G temp sensor (or a ky013, the math needs changing) some female female wires or solder setup

The NodeMCU can grab the time from your Wifi. No matter if the power goes out or there's a daylight time change, the clock should update to the correct time as long as you have wifi. ;) Powered by USB too, a great low power clock!

The possibilities don't stop there, you can add a small speaker to make an alarm clock. Add a humidity sensor and have it alternate between temp and humidity or just make it scroll through all the info marquee style.. add LED lights that you can control from your phone. Add a LDR light sensor, so it can determine if the lights are off.