I have posted it at Google groups and I will do it here to get more feedback.
One day I was reading Russian beekeeping magazine and found simple
tool that helps one in raising queens. It calls queen calendar and it
was made of two circles one inside other. Inner has 30 queen stages
from egg to queen starting laying eggs. Outer circle has 30 days on
it. Cutting two of this circle and rotating them one can know the
entire queen developing stages by date. You can see picture here:
Now, I took
their idea one step forward and wrote a little program look here: http://queencalendar.markfarm.com that does same thing. First enter
the day of the inspection and select queen development stage then
click Proceed and you will see the entire queen development stages
sorted by date, critical stages are in red. Please check it out and
let me know what you think.