👓 Coming of Age Day Calculator (成人式)

Seijin no Hi (成人の日, Coming of Age Day) is a Japanese national holiday held on the second Monday of January each year. It celebrates young people who have reached adulthood. On this day, local governments host seijinshiki (成人式, coming-of-age ceremonies) where new adults gather, often wearing traditional furisode (long-sleeved kimono for women) or suits, to hear speeches and celebrate with old classmates.

Historically, the age of adulthood in Japan was 20, and Seijin no Hi celebrated those who turned 20 during the current or previous school year. However, a major legal change took effect on 1 April 2022:

• The Civil Code revision lowered the age of majority from 20 to 18
• 18-year-olds can now sign contracts, get married (without parental consent for some matters), and vote
• But Seijin no Hi still celebrates 20-year-olds — the ceremony age was kept at 20 by consensus
• Drinking, smoking, and gambling remain prohibited until age 20

This means there are now two concepts of "adulthood" in Japan: legal adulthood at 18 (with rights like voting) and ceremonial adulthood at 20 (Seijin no Hi). The ceremony is the more culturally visible milestone.

The ceremony targets those who turned 20 between 2 April of the previous year and 1 April of the ceremony year (aligned with the Japanese school year). For the earlier childhood milestone at ages 3, 5, and 7, see our Shichi-Go-San calculator.

Your seijinshiki year is determined by your birth date and the Japanese school year system. The ceremony celebrates those who turned (or will turn) 20 between 2 April of the previous year and 1 April of the ceremony year. In practice:

Seijinshiki year = birth year + 20 (if born 1 April or earlier) or birth year + 21 (if born 2 April or later, due to the school-year cutoff)

The ceremony is always on the second Monday of January of that year. For 2026, that's January 12th. The exact date changes each year, but it's always a Monday holiday in early-to-mid January.

The 2022 law created an interesting situation: an 18-year-old is legally an adult (can sign an apartment lease, vote, get a passport without parental consent) but is not yet a "ceremonial adult" (no seijinshiki) and cannot drink or smoke. To check the kazoedoshi for these ages, see our kazoedoshi calculator.

1. Type your birth year (e.g. 2006).
2. Optionally enter your birth month/day for more precise eligibility.
3. Click Calculate to find your seijinshiki year.
4. The result shows whether you became legally adult at 18 or 20.
5. The seijinshiki ceremony date (2nd Monday of January) is shown.

When is Coming of Age Day (成人の日) in Japan?

Seijin no Hi is always on the second Monday of January. It's a national holiday. The exact date changes each year but falls between January 8th and 14th. In 2026 it's January 12th.

What changed with the 2022 law?

The Civil Code revision lowered the age of majority from 20 to 18 on 1 April 2022. 18-year-olds can now sign contracts, vote, and marry without parental consent. However, Seijin no Hi ceremony is still at 20, and drinking/smoking/gambling remain 20+. So there are now two concepts of adulthood: legal (18) and ceremonial (20).

How do I know which seijinshiki ceremony I attend?

You attend the ceremony in the year you turn 20, specifically if your birthday falls between 2 April of the previous year and 1 April of the ceremony year (aligned with the school year). Your local city hall will mail you an invitation.

Can 18-year-olds drink in Japan now?

No. Despite becoming legal adults at 18 in 2022, drinking, smoking, and gambling remain prohibited until age 20. The 2022 revision affected civil rights (contracts, voting, marriage) but not these age-restricted activities.

What do people wear to seijinshiki?

Women traditionally wear furisode (long-sleeved kimono), often elaborately patterned and rented for the occasion. Men usually wear suits, though some opt for hakama (traditional formal dress). Hair, makeup, and photography sessions are typically booked months in advance.

Is seijinshiki mandatory?

No, it's not legally mandatory. But it's a significant cultural event, and most local governments send invitations to all eligible 20-year-olds in their jurisdiction. Attendance is free and includes a ceremony, speeches, and photo opportunities with former classmates.

The furisode (振袖) is the iconic seijinshiki outfit for women — a long-sleeved kimono with elaborate patterns, often rented for the day at significant expense. Men increasingly wear suits rather than the traditional hakama, but some still choose formal traditional dress. Hair and makeup appointments are booked months in advance.

If you're planning to attend, contact your local city hall ("Seijinshiki" invitations are mailed to eligible 20-year-olds). The ceremony usually includes speeches by the mayor, photo sessions with old classmates, and sometimes a party afterward. It's one of the few times Japanese people reunite with their entire elementary/middle school class. For the age-13 shrine visit (十三参り), which is a similar coming-of-age ritual in Kyoto and some regions, see our jusan-mairi calculator.