4–6 weeks for most seasonal content. For major events like Christmas and Black Friday, start planning 8–10 weeks ahead. The early bird gets more search traffic.
Same format, seasonal angle. If you normally do tutorials, do a seasonal tutorial. If you do opinion pieces, share a seasonal opinion. Stay true to your format while adding the seasonal hook.
Every niche has seasonal angles. Finance: tax season, Christmas budgeting, new year saving goals. Fitness: summer body, new year goals, holiday eating. Look for the angle that connects your niche to the season.