Dear @Peter_Tobisson,
With the method to filter out days that have more tasks in the below post, you should be able to get the days that have 2 or more tasks
with credits to @shishir
Just brainstorming, I assume you will need to find a way to set daily a percentage to be spend on a task when there is more than one tasks available, because you can’t do more than 100% / day 
As @Ander already mentioned, we have in this community great approaches and let’s wait if we get more input.