Other examples using RTC - martinberlin/epaper-weather-station GitHub Wiki
Using DS3231 RTC and others that have a temperature compensated crystal you can also make a nice clock/ weather panel. Although the temperature reading is not very precise, might vary from 1 to 2 °C, is good enough to show it in your display.
This is a small 200x200 display connected to an ESP32-tinypico and a DS3231 RTC using only I2C. It wakes up every 2 minutes and reads the precise real-time-clock.
The example is here on Github to test it:
weather-station has some conditionals in the code. And when it's a 200 width display or smaller, it adapts the fonts and coordinates switching to that small dimensions.