Not quite so with Japanese productions. They may have things mapped out months in advanced, but actually 2D/CG/ voice work is probably closer only being about a month-1.5 months ahead. J-Dramas and the hero shows are usually done about 2-3 weeks before they air. I recall seeing with the Masked Rider series, actors were presented with flowers and gifts on their respective final day of filming. With the main actors, this was about 2-3 weeks (sometimes 1-1.5 weeks before) prior to the last episode being on the air. With anime, it's probably not terribly different.