This question already has an answer here:
Is it possible to use the present perfect to describe an action that happened earlier today and lasted for some time? As in:
I've slept for 16 hours today and that alone made me happy.
I've been on hold for four hours today! You just lost a frequent customer.
Wouldn't the simple past be more appropriate here, since these actions took place some considerable amount of time before the moment of speaking and are not quite linked to the present?
During my reaserch I only got more confused, as I've even encountered sentences like:
I've been playing the guitar for two hours today.
Which, I believe, is not correct at all?