Birthday Calculator

What Day Were
You Born?

Enter your birthday and discover which day of the week you arrived in the world.

Your Birthday

Works for any date from year 1 to present

The Seven Days

Each Day Has Its Own Character

☀️

Sunday

the Sun

Born on Sunday — a child of the Sun, radiant and warm-hearted.

🌙

Monday

the Moon

Born on Monday — a child of the Moon, intuitive and imaginative.

🔴

Tuesday

Mars

Born on Tuesday — a child of Mars, bold and courageous.

⚡

Wednesday

Mercury

Born on Wednesday — a child of Mercury, clever and communicative.

🌟

Thursday

Jupiter

Born on Thursday — a child of Jupiter, generous and optimistic.

💛

Friday

Venus

Born on Friday — a child of Venus, loving and artistic.

🪐

Saturday

Saturn

Born on Saturday — a child of Saturn, disciplined and wise.

Retro mid-century illustration of a desk flip calendar with a starburst design

Behind the Magic

How Does It Work?

01

Enter Your Date

Type in the day, month, and year of your birth — any date from year 1 onwards.

02

Algorithm Runs

We use Tomohiko Sakamoto's algorithm, a mathematically elegant formula for any Gregorian date.

03

Day Revealed

Your birth day is displayed along with its planetary ruler and a piece of folk wisdom.