National Sisters Day 2027 is on Sunday

About National Sisters Day

The day sets aside time to appreciate the particular mix of loyalty, rivalry and shared history that comes with having a sister. Families use it to get sisters together for a meal or an outing, swap childhood photos, or simply call one another. Many people also extend it to sisters-in-law, stepsisters and close women friends who feel like family.

The origin is thinly documented. The National Day Calendar registry, which tracks unofficial observances, says Tricia Eleogram of Tennessee founded National Sisters Day in 1996 to celebrate the spirit of sisterhood. No founding organization, proclamation or independent record confirms that account, and nothing is recorded about why the first Sunday in August was chosen. The day has no official status, and it is not set by any law.

National Sisters Day is separate from National Siblings Day on April 10, which honors brothers and sisters together, and from National Brothers Day in May. It is also unrelated to Raksha Bandhan, the Hindu festival that celebrates the bond between brothers and sisters. That festival follows the lunar calendar and often lands in August, so the two sometimes fall within days of each other.

Sources: National Day Calendar registry: National Sisters Day (archived 2025). How we check dates.

How to mark National Sisters Day

• Call, text or visit your sister and plan a day doing something you both enjoy.
• Dig out old family photos or home videos and share a favorite with her.
• Write down a memory from childhood that still makes you laugh, and send it to her.
• Invite your sisters, sisters-in-law and close friends for a summer meal or picnic.
• If you've drifted apart, send a short, low-pressure message to reopen the conversation.
• If your sister has died, cook her favorite dish or tell her story to a younger relative.

National Sisters Day dates