Gas heater question?

Hey everyone 2nd year as pool owner. Pool is In ground saltwater about 30,000 gallons
With a gas heater hayword h450.

My question is up here in New Jersey I estimated my gas heating cost about 10-15$ to heat the pool

For a day to day an half if I raised it like 8 degrees night before people came over,
Does anyone have expirence just leaving heater on all the time? Is it more cost effective to leave it at certain temp all summer then to raise it dramatically for 2 days a week ?

Thanks for any input