Hi there!

In few words, the launch date does not matter a lot as long as you are following with a continuous marketing plan all the year. It is better to tune your lunch date according to your marketing campaign than connecting it to the seasonal event. The timing of your launch only matters if your website is already ranked or has a good authority associated to it. Launching a website is not like opening a local shop. The launch date is defined by the effectiveness of your marketing campaign. In other words, your question must be rephrased as: "When is the best time to launch my first marketing campaign for my newly created website?". In that case, you will need to describe in details what kind of website you have and how are you planning to market it.

I would be able to give you a more accurate answer if you explain to me what kind of website are you planning to launch or what products mainly are you selling.

Hope that helps!