Check this to create your own java clocks
You can add anything in a java clock from a simple hh:mm clock to date / month / week / texts etc
Possibilities are endless, depends on how you use it
You can watch the above video to learn how to use it.

Here is a detailed guide (thanks to @GZMTN) check this telegraph to learn how to make your own clock -
https://telegra.ph/Custom-Java-clock-in-DSB-03-08