Did you check your phone time last Monday? If you did and set the intention to change it, did you notice that the time spent on your phone dropped this past week?
Setting a clear intention and telling our mind what you want is a powerful tool to make a change in your life. When say what you want, your subconscious mind will start working to make that thing happen, often without your conscious mind even noticing. In cases like phone use, my clients report that their time dropped even if they did not think about “I have to use my phone less” at all.
Give your mind something to work on, and watch it do its magic.