Clock with Nextion display

I want to build a Clock using nextion display. In which mode can I do it without esp module ?

Autonomous mode.

If you don't want to use an ESP module, which in this context would be used to get the current time from a network time server (NTP protocol), then you must use a real time clock (RTC) which has a backup battery so on system restart, the time is automatically set to the correct time.

Thanks you for your reply. Can you give me more detail to do this? COnsider also that I want implement a Clock and also I want to use Nodemcu with esp8266 to other operation.

The 'enhanced' Nextion displays include a RTC built in, no need for an external clock module of any kind. No idea how accurate they are.