Originally Posted by
Egor
More precisely you need at first get 3000 miles in any 365 day period and then 16000 miles in any 365 day period (but 3000 miles for your silver are excluded). Also Y fare on UA/CO would lead to 150%, 750 minimum
No, CO Y fares only earn 100%.
That said, OP said that they use cheap fares (definetely not Y)..
The rest of what you posted is right on..
Remember, 2012 is a leap year, so you have 1 day less than you think