COLUMBUS, Ohio (WTVN) -- It seems like we're always trying to guess when the best time to fill up with gasoline is. Most of the time many of us seem to gamble incorrectly, but an analysis of gas prices over the last four years by did find some clear patterns.

"Prices most likely go up Monday and Thursday in the region," said Patrick DeHaan, a senior petroleum analyst with

DeHaan says the best time to buy gas is over the weekend. That's when markets are closed and prices tend to be more stable.

"By in large the best time is going to be Monday morning before work," he said. gets its data from users of the website and a mobile app. It also alerts users about price spikes.

Last year, GasBuddy found Saturday's price was lower than the week's average 32 times. Tuesday's prices were only lower than the week's average 17 times.

GasBuddy found that more than 30 states see the lowest prices of the week during the weekend. Pennsylvania and West Virginia bottom out on Saturday while Michigan's lowest gas prices are usually on Friday. Monday is the time to top off in Indiana and Kentucky.