Q1.
Isn’t it fascinating that the calendars which determine our routines on Earth are linked to the motions of objects far beyond our planet?
Answer
Yes — and it is no coincidence. Every unit on a calendar is simply a count of something moving in the sky.
| Calendar unit | What it actually counts | How long it takes |
|---|---|---|
| Day | One rotation of the Earth on its own axis | about 24 hours |
| Month | One full cycle of the Moon’s phases, new moon to new moon | about 29.5 days |
| Year | One revolution of the Earth around the Sun | about 365.25 days |
Why it happens: a calendar is useful only if it lets you predict — when to sow, when the rains will come, when a festival falls. You can predict only what repeats regularly. Long before any clock existed, the sky was the one thing that repeated perfectly: the Sun rose every day, and the Moon went through the same set of phases again and again. So humans counted the sky, and those counts became the calendar.
The catch: the three motions do not divide neatly into one another, and that is why the world has more than one calendar.
12 lunar months = 12 × 29.5 ≈ 354 days
1 solar year ≈ 365.25 days
365.25 − 354 ≈ 11 days short every year
1 solar year ≈ 365.25 days
365.25 − 354 ≈ 11 days short every year
- A purely lunar calendar (the Hijri calendar) simply lets the months drift, so Ramzan slowly moves through all the seasons.
- A purely solar calendar (the Gregorian one on your wall) keeps the seasons fixed and adds one leap day every four years to soak up the leftover 0.25 day.
- Indian panchangs are luni-solar: the months follow the Moon, but an extra month (adhik maas) is inserted about every three years so that festivals stay in their proper season.
The calendar printed in this chapter shows Chaitra, the first month of the Indian national calendar. In 2025 Chaitra ran from 22 March to 20 April — exactly 30 days, and its start is fixed by where the Earth is in its orbit, not by any decision on Earth.
Did you know? The Moon is about 3,84,000 km away and the Sun about 15 crore km away. The date on which you celebrate Holi, Eid, Diwali or Pongal is settled by where those two distant bodies happen to be — which is why the same festival falls on a different English date each year.