I don't. Who does??

When was the last time a city dweller needed to worry about where the Earth or moon was?

Things we do need to know:

• How many days in a row do I have to work

• When do I get my next paycheck

• When is X product coming out

• How long do we have to put up with X politician

• When should I plan a vacation

• When will it get colder or warmer

Except for maybe the last 2 questions, all of the above can be answered by a calendar that has nothing to do with astronomy whatsoever.

Farmers and scientists can continue to use the astronomical calendar of their choice. Perhaps make one that is specifically designed for them, in maybe a S%.M% format, where S% is the percentage of Earth's solar orbital period we are currently at, and M% is the moon's orbit.

For the rest of us ordinary folk, we would be fine with a "Human Calendar" that is simply a cycle of working days <-> weekends, with some holidays thrown in every N weeks.

Say a 4/2 or 4/3 (work/rest) day week, 4 weeks in a Human Month, and an 8-10 day holiday every 3 such months.

A Human Year could be the equivalent of 9 or 10 months of the current calendar, the average duration a new person takes from conception to birth. :)