I can only speak for my airline (RAH)...

I send an email to the Leave of Absence desk for drill prior to the bids being released. So to get my drill dates off for August, I usually try to submit my military schedule no later than July 5. If I know my drill dates for several months out, I will give them the dates I have, but I try not to schedule more than 3 months out because the dates can change.

When the bids come out on FLICA, my drill dates show as a pre-assigned activity, so the system will not award trips on those days. You are not required to provide orders, but generally if I will be out for a week or more I submit orders with my request.

Feel free to PM me if you have other questions!