Rokuyō

It's fitting that Senshō, the first day of the Rokuyō cycle, aligns with the classic "first come, first served" philosophy. In other words, if you snooze, you lose.

In the Rokuyō system, Senshō's kanji suggest that success favours those who act quickly.

However, "first" doesn't necessarily mean waking up at the crack of dawn. Generally, Senshō means that luck is on your side in the first half of the day, but misfortune lurks in the afternoon, like an unwanted email from your boss at 4:59 p.m. (See how Rokuyō defines the "second half" of the day.)

An alternative interpretation suggests that the entire day is favourable for starting new ventures, but even this depends on context.

Real-world applications
(and mildly questionable analogies)

• If a shop only has 300 units of the latest iPhone, luck means queuing early enough to secure a spot.
• If you’re using superglue, success depends on positioning the material correctly before it sets. A delayed reaction could mean spending the afternoon with your fingers stuck together, which is technically still “bad luck in the afternoon”.

Overall, Senshō teaches that taking action swiftly leads to success, while hesitation results in missed opportunities. This aligns with the traditional Japanese emphasis on preparedness, timing and initiative.

Senshō in different fields

• Sport: The psychological edge (or excuse?)
  While most modern teams don’t officially follow Rokuyō, some athletes do - especially in martial arts, baseball and horse racing. A competitor who believes Senshō is lucky might feel a mental boost. Meanwhile, their opponent, who ignores the Rokuyō calendar, remains blissfully unaffected (or just blames their loss on something else).
• Gambling and pachinko parlours: where luck meets maths
  Casinos and pachinko parlours don’t openly promote Rokuyō superstitions, but superstitious gamblers might prefer to start playing in the morning on a Senshō day. If enough people believe in it, then statistically speaking, Senshō will be lucky for the casino’s profits.
• Entertainment (Senshōwbiz)
  For connoisseurs of less financially hazardous hobbies, Senshō once played a role in scheduling kabuki, Noh and other traditional performances. Film studios and record labels also used to favour Senshō mornings for premieres, but these days, streaming platforms are less concerned with lucky days and more with algorithms.
• Weddings and ceremonies
  Senshō is the budget-friendly Taian alternative, especially if the couple isn’t too worried about the “bad luck in the afternoon” part. Wedding halls and Shinto shrines might even offer discounts for Senshō-day ceremonies, which is a fortune worth considering.
• Business
  Senshō is where tradition meets spreadsheets. Some business owners and stock traders still believe it's a smart move to launch a project, sign a contract or seal a deal in the morning on a Senshō day. Ironically, these same advocates of 'acting decisively and without hesitation' on Senshō days, can be remarkably slow in adopting modern and less superstitious business practices.
• Travel and moving house
  Adherents of the 'Senshō Suitcase Theory' prefer to set off in the morning on a Senshō day, believing early departures ensure smooth journeys. Of course, since delays happen regardless of fortune-telling, leaving early is just common sense, whatever day it is.
• Medical appointments and surgery
  Older generations sometimes prefer scheduling major surgeries on Senshō mornings, believing it increases the chances of success. However, hospitals and clinics run on science, schedules, and the reality that medical staff don’t consult Rokuyō before booking your slot.

Despite growing scepticism, Japanese calendars still mark Rokuyō dates, and some people check them out of curiosity (or as a convenient excuse for rescheduling meetings). Originally, Senshō focused on the concept of “early", but over time, its meaning has evolved into the widely accepted “Good luck in the morning, bad luck in the afternoon".

If you're interested in luck the other way around - where the morning is unlucky, but the afternoon gets better - then see Sakimake.

Also known as
Senshin, Sen'nin, Senkachi, Sakigachi and Sakikachi