Christmas in July is not new. Excerpt from: https://en.wikipedia.org/wiki/Christmas_in_July
In 1935, the National Recreation Association's journal Recreation described what a Christmas in July was like at a girl's camp, writing that "all mystery and wonder surround this annual event."[4]
The term, if not the exact concept, was given national attention with the release of the Hollywood movie comedy Christmas in July in 1940, written and directed by Preston Sturges.[5] In the story, a man is fooled into believing he has won $25,000 in an advertising slogan contest. He buys presents for family, friends, and neighbors, and proposes marriage to his girlfriend.[6]
In 1942, the Calvary Baptist Church in Washington, D.C. celebrated Christmas in July with carols and the sermon "Christmas Presents in July".[7] They repeated it in 1943, with a Christmas tree covered with donations. The pastor explained that the special service was patterned after a program held each summer at his former church in Philadelphia, when the congregation would present Christmas gifts early to give ample time for their distribution to missions worldwide.[8] It became an annual event, and in 1945, the service began to be broadcast over local radio.[9]
The U.S. Post Office and U.S. Army and Navy officials, in conjunction with the American advertising and greeting card industries, threw a Christmas in July luncheon in New York in 1944 to promote an early Christmas mailing campaign for service men overseas during World War II.[10] The luncheon was repeated in 1945.[11]
American advertisers began using Christmas in July themes in print for summertime sales as early as 1950.[12] In the United States, it is more often used as a marketing tool than an actual holiday. Television stations may choose to re-run Christmas specials, and many stores have Christmas in July sales. Some individuals choose to celebrate Christmas in July themselves, typically as an intentionally transparent excuse to have a party. This is in part because most bargainers tend to sell Christmas goods around July to make room for next year's inventory.[13]
Or, if you prefer (or are from the south): southernliving.com/christmas/how-did-christmas-july-start
Christmas in July has become such a cultural staple each year that you may not have even thought about who first dreamed up such a cheery, potentially cheesy, midsummer celebration. Well, as it turns out, per Country Living's reporting, it started right here in the South. (No, it wasn’t marketers!) We can’t say we’re surprised though. Christmas in July started 84 years ago on July 24th and 25th in 1933 at a girls’ camp called Keystone Camp in Brevard, North Carolina.
"I never thought it was unique to us," Page Ives Lemel, the current director of Keystone Camp, said in an interview. "It seems like something other camps would do." But not so. According to the camp’s 100th anniversary celebration book, the first time anyone celebrated “Christmas in July” was at Keystone, per the request of camp co-founder Fannie Holt.
"Miss Fannie was such a character: a whimsical, dreaming, creative type who added all of this uniqueness to the program," says Lemel. "Most camps number the cabins to identify them. Here, we have Crabapple, Skylark, and Crow's Nest, for example. Instead of junior and senior campers we have Elves, Pixies, and Dryads."
What is good for the goose today will also be good for the gander tomorrow.