I know Disney will tell you the exact date to call for your ADR's, but if you are like me and always forget to ask, this website is faster than calling Disney back. And I am always paranoid that I will make a mistake counting back 180 days on my own and be off one day and miss out on my first choice for CRT! I saw this on allears this morning.
http://pscalculator.net/allearsnet/pscalcae.php
http://pscalculator.net/allearsnet/pscalcae.php