The FediTags website is online now, offering an overview of common and daily #hashtags.

https://feditags.info

What are daily #hashtags?

Daily hashtags are hashtags that are associated with specific days of the week or recurring events. They are often used on social media platforms like #Mastodon to encourage users to share content related to a particular theme or topic on a specific day. Examples of daily hashtags include #ThrowbackThursday, #MotivationMonday, and #SelfieSunday.

For an overview of most used #DailyHashtags see this thread or visit https://feditags.info/tags/daily.