Recognizing that “casual days” make employees “really happy,” Target Corp. has loosened its dress code for its office workers and no longer requires traditional business threads.

The new “Dress For Your Day” dress code covering employees who are not on the retail floor took effect this week and comes as the Minneapolis-based retail giant slogs through a challenging period that has involved layoffs, a reputation-damaging data breach and costly stumbles in its Canada expansion.

About 14,000 corporate employees can now report for work in garb as laid-back as jeans, golf shirts and even sleeveless blouses for women. Of course, a company memo read, “red and khaki is always appropriate,” the color combo required for Target’s retail staff.

“We all know that casual days, weeks or months make team members really happy,” the memo read. “We also know that life’s a little easier when we have more choices — and less dry cleaning.”

The policy comes with clear guidance about what to wear depending on what’s going on that day.

“If you have a big day, you might wear something like a dress or a suit, or maybe even dressy jeans and a blazer,” the memo read. “If your day is more low-key, jeans and a nice polo or a sweater might be the answer.”

Employees helping in the community on a particular day can report to work in a Target Volunteer T-shirt.

Target spokeswoman Molly Snyder said the shift came because the company recognized that “people want to express themselves and show some creativity and make those decisions themselves.” Previously, Target limited casual wear to Fridays.

Snyder said she chose jeans and a sweater for work on Wednesday, then felt her day on Thursday called for a more businesslike appearance.

As she went about her job this week in downtown Minneapolis, Snyder added, “it’s been fun to see the team really embrace this and be enthusiastic.”

The list of don’t-even-try-it clothing options remains lengthy: raggedy shoes, flip-flops or certain types of sandals; clothes with offensive words or graphics; shorts, overalls, sweats, workout clothes; and hats or caps (unless for a medical need).

Also better left at home are halter tops and other types of revealing clothing, and leggings unless properly covered.