Hi @rayhanul, what do you mean exactly?
The Steemit #monthlyauthorchallenge?

Here you can find my start article of this challenge with more information: https://steemit.com/steemit/@future24/steemit-challenge-idea-the-monthly-author-badget-challenge

You can find the rules for participating in my article above for example and the challenge is always restarting at the first of a new month. So the next start is the 1. Juli. 👍