Question

why must one be punctual ​

Answer 1

Answer:

Punctuality is a sign of professionalism and helps you stand out as a reliable and trustworthy employee. If you don't get your part of a project completed on time, you keep others from being able to finish their tasks. Being punctual helps you establish your reputation as a dependable and consistent worker.

so be punctual and thank me

Answer 2

Answer:

So that you do not miss out some important things in your life