So how I understand, I would get the same amount if I stake just 1 day per year in compare to 1 year 24/7?
No you get most when you stake 24/7
Sure if you leave it offline for a year, the day you stake you'll get many more stakes than a regular day in 24/7. Maybe the equivalent of 2-3 days
If you can't leave it on all the time, you probably don't lose too much if you leave it just 12 hours a day or open it every other day