Hi
@ElizabethV8You can only delete messages in a thread if the message senders, or the owner of the team, have permissions to do so within the messaging policy, if the messaging policy does not allow this then it cannot be deleted. If the message sender has, they can delete their own messages. If the team owner has they can delete on behalf of other users.
https://docs.microsoft.com/en-us/microsoftteams/messaging-policies-in-teams#:~:text=Create%20a%20cus....
In addition, you can use retention policies to delete chats and conversations older than x date, so for example, delete everything older than 30 days.
https://docs.microsoft.com/en-us/microsoft-365/compliance/create-retention-policies?view=o365-worldw...You would need the required licencing for this which you may or may not have. In addition, applying the retention policy would apply that to all chats in the Team not just that particular one.
However, what isn't possible is a functionality to say, I want to delete everything before this particular post, in the teams client. However, as outlined there is a few options. In addition, you may want to consider doing this in a few other ways. The Shifts App in Teams has a time clock where you can clock in and out of your shift. You could also potentially create a Power App which shows if someone is in or out the office. You could do it with a list like a time sheet.
Hope I have given you a few options and have answered your question
Best, Chris
