This year, dads are battling it out with moms for their loved ones’ wallets.

The nation’s major retailers are turning their attention to Father’s Day, which long has lagged behind Mother’s Day among the most important holiday sales periods. By expanding shopping hours and advertising earlier and more aggressively for Father’s Day – which this year falls on Sunday – merchants are hoping to provide a big sales boost during summer’s lull.

Sears Holdings Corp.’s Sears, Roebuck and Co. stores declared June as the season for dads, elevating it to a “Christmas-like status,” according to Corinne Gudovic, a company spokeswoman. The retailer recently dispatched caroling dads who sing holiday jingles with Father’s Day themes – “O’ Plasma Screen” – at malls in the New York and Chicago area. It started its Father’s Day ad campaign June 4, three weeks earlier than a year ago and is offering a Father’s Day gift card for the first time.

Meanwhile, Home Depot Inc., the nation’s largest home improvement merchant, expanded its Father’s Day advertising beyond circular ads this year, launching a TV and online advertising campaign. It’s also pushing a wider array of gifts beyond the tool kit to include grills and pressure washers.

A sign advertises Father's Day gifts as a shopper buys building materials in the background at a Home Depot store.

“This year, Father’s Day is very important and very opportunistic,” said Marshal Cohen, chief analyst at NPD Group Inc., a market research firm based in Port Washington, N.Y. “But with that comes greater risk. You have to spend more to market and you have to risk more with greater inventory.”

But retailers are willing to take such risks, worried that higher gasoline prices and inflation will keep shoppers away this summer and reverse a solid trend in consumer spending this year. Merchants see Father’s Day as the last big sales opportunity before the back-to-school season kicks off in August.

The Sears Caroling Dads practice their performance at the Sears store in Newport Center Mall in Jersey City, N.J.

According to the National Retail Federation’s survey of 7,000 consumers, shoppers plan to spend $9 billion on Father’s Day gifts, up from a planned $8.2 billion a year ago. Still, that lags behind Mother’s Day, with sales expected to reach $13.8 billion this year, up from $11.4 billion, based on a consumer survey.

Mother’s Day is the third biggest holiday sales generator, behind the winter holiday and back-to-school seasons; Father’s Day is sixth, with Valentine’s Day and Easter ranked as fourth and fifth, respectively.