Hi @MJS,
You could following these steps to approach that:
1. Initialize several variables to store Today, submit day, and count days.
2. Create a Do until action to count days, if today does not equal to the weekend, add 1 day based on the count days variable, or do nothing. For each run, we should add 1 day to the Today variable.
dayOfWeek(variables('Today'))



PS: The default looping limits is 60, we could set it to 5000 to make it could count 5000 days difference.

I export the Flow and upload it, you could click the zip file under the post and import it into your Flows to test it.
Best Regards,
Community Support Team _ Lin Tu
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.