Do you know what's great about Monday? Gas prices.

GasBuddy said so far this year, Monday is the cheapest day to buy gas in 23 states. Sunday's not a bad day either. The worst days are Thursday and Saturday.

Why? GasBuddy thinks it could be because Energy Information Administration releases its report every Wednesday. Depending on if the data in that report is expected or a surprise could force gas prices to increase.

“The rise in average prices towards the weekend could be to blame on an influential report from the Energy Information Administration (EIA) issued weekly on Wednesdays, which could push prices higher the day after, depending on if data in its report is as expected or a surprise,” Patrick DeHaan said, senior petroleum analyst at GasBuddy. “Since commodities trading isn’t active over the weekend, it typically allows stations to ‘let it ride’ over the weekend, culminating in lower prices by the start of the work week.”

The best days to top off your tank are Tuesday and Friday.

  • In 2017 so far, Monday is the best day of the week in 23 states.
  • In 2016, Monday was the day featuring the lowest average gasoline prices in 36 states, while eight states saw Tuesday as the victor.
  • In 2015, Monday saw the lowest gasoline prices in 22 states.
  • In 2014, Wednesday was the day of the week offering the lowest average gasoline prices.