The phrase”Let’s call it a day”

I am a little bit confused as to whether it is correct to use the above phrase mentioned in the subject in the following situation:

You have a part in a company/school’s seminar which consists of many parts. Each part is given by a different person. The seminar itself is repeated each week with similar parts. When you finish your part, would it make sense or sound right to say, “We’d like to call it a day for now. Look forward to your participation next time.” Although my part is finished, the seminar itself will continue with different parts being delivered, which means the participants will not be going home.

I understand the meaning in the dictionary and it’s basic usage, but some reason it didn’t sound right to me.
If a native English speaker could give me the answer, it would be appreciated.