It’s good to pause to 振り返ってみる (furikaette miru, look back on things) every now and then. I did so recently and was surprised to see that I wrote 59 Bilingual page columns for The Japan Times in the decade that just ended, the bulk of which were published from 2014 onward.

So this is my 60th article and a start to a new decade, the 2020s, which got me thinking about the number 60 in Japanese. Conveniently for the conceit of this column, the number 60 is associated with a new start in Japan because of the phenomenon known as 還暦 (kanreki, 60th birthday).

In English-speaking countries we have various retirement ages, some dictated by legal policies and others by tradition. We also have the phrase “over the hill,” which is associated with the ages of 40, 50 and 60, depending on whom you ask.

還暦, on the other hand, is strictly defined as turning 60 because it is linked with the 十干十二支 (jikkan jūnishi, 10 calendar signs and 12 zodiac signs), which originated in China.

Readers may be more familiar with the 十二支 (jūnishi, also known as “12 earthly branches”), the set of animals that create the zodiac calendar. Every 12 years a person returns to the zodiac of their birth and becomes a 年女 (toshi onna, literally “woman of the [zodiac] year”) or 年男 (toshi otoko, “man of the [zodiac] year”).

What you may not know is that this 12-animal calendar overlaps with the 十干 (jikkan, also known as “10 heavenly stems”), and because the 最小公倍数 (saishō kōbaisū, least common denominator) of 10 and 12 is 60, it creates the 干支 (kanshi, sexagenary calendar/cycle).

I’ll let you research your own year and find out what it may suggest about you (if you believe in that sort of thing), but what all this really means is that when you’ve reached 60, you’ve gone through all 59 possible combinations of the 10 calendar signs and 12 zodiac signs and have returned to the calendar and zodiac sign of your birth. The 還 in 還暦 is another way to write 帰る (kaeru, return), and 暦 (koyomi) means calendar, referring to the 干支. You’ve completed a cycle and are now starting a new lap.

So while “over the hill” has negative implications about an impending decline, 還暦 is more positive and celebrates having had a long life and the start a new life of sorts.

As you can imagine, there is an appropriately festive party associated with this birthday. It usually involves 外食 (gaishoku, eating out) at a restaurant, and it can be a large or small group. The person being honored wears a red ちゃんちゃんこ (chanchanko, sleeveless jacket/vest) and 頭巾 (zukin, beret-like hat/hood).

The history behind the clothing choices seems to be somewhat apocryphal, but is attributed variously to 魔除け (mayoke, charm against evil spirits) powers of the color red, the association of 赤い (akai, red) with 赤ちゃん (akachan, babies) — given that the celebrant is “returning to being a babe” — and the child-like, sleeveless look of the ちゃんちゃんこ.

I had always associated 還暦 with men, and while it is celebrated by women now, a few sites online note that it began as an inheritance celebration, a way for the head of a household to put his estate in order late in life. However, these sources also noted that women may be less likely to draw attention to their age in the first place.

So what do you say to someone who is celebrating?

The simplest phrase is, of course, 還暦おめでとうございます (kanreki omedetō gozaimasu, congratulations on your kanreki/turning 60).

It’s also a good moment to emphasize the person’s continued potential rather than a decline. Here’s one possibility that you can adapt for letters or cards: ますますのご活躍を期待しております/お祈りいたします (Masu-masu no go-katsuyaku o kitai shite-orimasu/o-inori itashimasu, I hope that you’ll be even more active). お祈りいたします can be used by anyone, but 期待しております is usually used by older people speaking to someone younger than themselves.

And in this age of social media, what do you post on your own accounts when you’re the one celebrating?

You can start by thanking everyone for the messages: 還暦祝いのメッセージをありがとうございます (Kanreki iwai no messēji o arigatō gozaimasu, Thank you for the celebratory kanreki messages).

Then perhaps you can take a moment to suggest you’re taking advantage of your time: 一日一日を大切に過ごしていきたいと思っています (Ichinichi-ichinichi o taisetsu ni sugoshite ikitai to omotte-imasu, I’d like to go forward making sure every day really counts).

I hope to reflect the same spirit in my future columns, and I’ll do my best to get in at least another 60 in this decade!