Where can I find the times of world economic news releases?

Answer 1

Lots of things are quarterly or annual. If you hear about crop reports, likely they will release next year's about one year later.

http://finance.google.com/finance
might tell you of *past* releases

If you are familiar with law, this may tell you when certain
organizations are *required* to make reports, and who
would get the information first.

If you are rich (Martha Stewart) your broker might be happy to pass along news (even if it is illegal) related to your investments.