I used to check the Dow multiple times per day, and then check the Dow futures before the markets reopened the following day. Every day. Not sure why. All that info never influenced any of my financial decisions as I still put away the same amount every month into my retirement accounts.
Last week, I decided to quit doing that and to just look at the markets (and my account balances) once per week. The only difficulty is that when I open the NYTimes website, the market info is right at the top, so I have to quickly scroll down a bit to avoid it.
After just 10 days of this practice, I am deciding that I like it--I hadn't thought that watching the Dow stressed me out, but maybe it did--or maybe it was noise that I just didn't need rattling around in my head all day.
Soon, I may decide to look at the markets and my account balances just twice a month--and then who knows, maybe once per month or even less often.