If you’re perpetually tardy, it’s time to change your ways.

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We’ve all been there: Our hair wasn’t cooperating; we had to change outfits four times; and the traffic on the way to the party was straight out of New York City. No matter, we tell ourselves as we roll in five…ten…twenty minutes late to the party. We’re just “fashionably late.” Or are we? Here, Diane Gottsman, one of our favorite etiquette experts and founder of the Protocol School of Texas, schools us on what it means to be fashionably late.

Diane Gottsman, Founder of the Protocol School of Texas

Photo Courtesy of Diane Gottsman

“It’s a confusing term and often an excuse for those who lack time management skills,” says Gottsman. “Some people were ‘taught’ that it’s acceptable to arrive late, but in reality, it’s rude to keep a host waiting and wondering.”

She also notes that though historically, it may have been considered acceptable to show up late in order to make an entrance, it’s never polite to keep the hosts or other guests waiting.

Here, Gottsman shares the appropriate times to arrive at various social and business engagements:

Weddings, Funerals, Baptisms, and Other Formal Events

“Arrive in enough time to take a seat before the ceremony begins.”

Theater Performances

“You should arrive early (never late), and take your seat.”

Fundraisers

“If the official check in time states 6:00 pm, and the dinner begins at 7:00 pm, you can arrive at 6:15 to 6:30 and enjoy the cocktail hour while other guests are checking in.”

Open Houses

“You can come in or out during the timeframe stated on the invitation.”

Wedding and Baby Showers

“You should be there on time – not 15 minutes late.”

Job Interviews

“A job interview can go terribly wrong when the interviewee runs late. He or she should arrive 10 minutes in advance and take a seat in the lobby. There is no such thing as fashionably late when you are looking for a job!”

Bottom line? “Keeping anyone wondering if you are going to show up is rude,” says Gottsman. “It’s fashionable to be on time, 5 to 10 minutes is a grace period. Also, you certainly don’t want to show up to your host’s home or event early! They are attending to last-minute details.”

WATCH: How to Subtly Signal That the Party's Over

Guess we’ll have to start showing up to parties “fashionably on-time.”