Creating a Cornish bank holiday on St Piran's Day could bring an extra £35 million into the county, according to tourism leaders.
Figures from Visit Cornwall suggest there is potential for an increase in tourism worth £20-£35 million to the county if the May Day Bank Holiday is moved to St Piran's Day for Cornwall and October for the rest of the country.
They identified this option as "the most economically advantageous" for Cornwall.
The tourist board predicted an extra tourist spend of £20 million for Cornwall if the bank holiday is moved to October for the entire country.
Malcolm Bell, head of tourism at Visit Cornwall, said having a different bank holiday in Cornwall would help the county to stand out.
"It's quite a strong marketing message because people like to go somewhere different but familiar," he said.
The figures are included in a report due to go before the full Cornwall Council on November 29.
It recommends the council writes to the Government, asking that any change to the May Day Bank Holiday should lead to the creation of a public holiday in Cornwall on March 5, the day the patron saint of tin miners is celebrated.
The Government is currently in the process of consulting on proposals to move the May Day Bank Holiday for the whole country to a new date.
Suggestions have included creating a UK Day or Trafalgar Day in October, or moving the May Day Bank Holiday to St George's Day on April 23.
However, campaigners in Cornwall have grasped this opportunity to make a bid for the county to have its own public holiday on St Piran's Day.
Liberal Democrat councillor Ann Kerridge, who put forward the original motion calling for Cornwall to have its own public holiday, said: "The report shows very clearly that a St Piran's Day bank holiday is good for our culture, good for tourism and good for Cornwall.
"The council needs to be demanding that government allows Cornwall to grab all these advantages by allowing us to celebrate St Piran and Cornwall on March 5."
Derek Phillips, chairman of South West Chambers of Commerce, said: "I don't think businesses outside of Cornwall would have strong views but within Cornwall I would imagine there would be support and this would give a boost to many of the businesses within the county."
David Shephard, chairman of the Devon Federation of Small Businesses (DFSB), welcomed proposals to spread UK bank holidays more evenly throughout the year.
But he was dubious about the practicalities of Cornwall having a separate public holiday to the rest of the country.
He said: "These sorts of things can be celebrated without necessarily going to ask the Government for a national holiday.
"If the Cornish want to celebrate St Piran's Day I see no reason why they shouldn't but I think [a separate public holiday] would be difficult practically.
"They're not a country in their own right, they're an essential part of England."
However, Mr Shephard said he wished Cornwall luck if it did pursue the campaign, and suggested a Cornish bank holiday could provide a boost for the rest of the Westcountry too.
"If there are lots of things going on in Cornwall over that period then people are going to come down through Devon and Devon would benefit," he added.