Starting a new habit is demanding. It creates a high cognitive load.
The first day you do a new dance, a new job, a new workout, you are completely worn out. You’re tired, it requested a lot of energy and focus.
You can’t expect to have the wish and ability to do it on a weekday after you’ve worked, done the shopping, taken care of your family, etc.
Starting during the weekend has the advantage to be already a rupture on your weekly routine. You can create time and space to take it easy and start the new habit.
By starting during the weekend, you’ll be happier, more focused, more relaxed, and you won’t be feeling guilty every day of the week for postponing!