Hi @Itay_Kurgan , indeed! I noticed this the other day whilst training a client but I forgot to check it out later. It definitely addresses the SLA issue for time spent in sections/custom fields etc and it works with task dependencies and task duration in the same project’s Timeline, Gantt or Calendar views. However, visually, weekends are still displayed as defined by the user’s Settings>Display settings which are still a bit limited to just ‘conventional’ 2-day weekends - this is a bit unfortunate as a user cannot visually see non-working dates in these project views - I’ve created a new English Forum > Product Feedback for this, here.
I agree with you that this could definitely be a global setting for the company. Would you like to create a new topic in the English Forum > Product Feedback category, @Itay_Kurgan ?
@Forum-team , is this feedback request fully launched? (can you mark as launched?) I got exactly what I asked for. 
Thank you, 
team!