What is the difficulty with the use of a lunar calendar? It isn't clear when a lunar month begins and ends.

Over time, the months cycle through the seasons.

It didn't help with telling time during the day.

The Moon isn't visible when it's in a new phase.

I'm learning about the periodic tables and what each subject's configuration is. for example, hydrogen is 1s^1, but i don't understand how you get that. can someone me understand how to figure out how to figure this out? sorry if the question makes no sense, but it would really a lot if you could me understand! you so much if you can!