HELLO, we are delighted you have began this contest with us. Concerning your question, just as you have done, you can start from day one. It doesn't matter if it sync with the real date of the month.
Thanks for sharing your content in The Blogging Challenge Community, we will LOVE if you keep doing it. If you are not in our Discord SMILE server please feel free to join, here we share more with the members, you can also know all the updates and new challenges! If you want to support us, here I leave you the curation trail so we can support other authors participating in the challenge and keep making more questions.