NCERT Solutions for Class 4th Maths Chapter 12 Names of the months in other calendars — Let Us Explore
Book page 177 Updated on2026-09-19
Q1.
Find out when the year begins in each of these calendars.
Answer
Ask at home or look at a panchang or a wall calendar. Different calendars start the year on different days.
Sample answer:
Calendar
The year begins on
Around this English month
Hindu (Vikram Samvat)
Chaitra Shukla Pratipada (Gudi Padwa, Ugadi)
March or April
Islamic (Hijri)
1 Muharram
moves back about 11 days every year
Sikh (Nanakshahi)
1 Chet
14 March
Tamil
Puthandu, 1 Chithirai
14 April
Bengali
Pohela Boishakh
14 or 15 April
Why it happens: The English calendar follows the Sun, so its New Year is fixed on 1 January. The Islamic calendar follows the Moon only, so its New Year keeps sliding earlier.
Q2.
Check how the names of the months in these calenders correspond to the months in the English calendar.
Answer
Put the two lists side by side and see which English months each one covers.
Sample answer:
Hindu month
Falls in
Hindu month
Falls in
Chaitra
March–April
Ashwin
September–October
Vaishakh
April–May
Kartik
October–November
Jyeshtha
May–June
Margashirsha
November–December
Ashadh
June–July
Paush
December–January
Shravan
July–August
Magh
January–February
Bhadrapad
August–September
Phalgun
February–March
Each of these months sits across two English months, not inside one. The Islamic months (Muharram, Safar, Rabi-ul-Awwal, …) do not stay with the same English month at all.
Why it happens: These months are counted from one new moon to the next, which is about 29 or 30 days. That does not match the English months, which have 28 to 31 days and are counted from the Sun.
Q3.
Identify the months from the Hindu/Islamic/Sikh or any other calendar in which some of the important festivals of the community fall.
Answer
Take the festivals your family keeps and find the month each one falls in.
Sample answer:
Festival
Month of the community calendar
Holi
Phalgun (full moon)
Raksha Bandhan
Shravan (full moon)
Janmashtami
Bhadrapad
Diwali
Kartik (new moon)
Guru Nanak Jayanti
Kartik (full moon)
Baisakhi
1 Vaisakh
Id-ul-Fitr
1 Shawwal
Id-ul-Zuha (Bakrid)
10 Zil-Hijjah
Tip: Notice how many festivals sit on a full moon or a new moon day. That is why their English date changes every year.
Q4.
Identify the dates of the new moon and full moon in your community’s calendar every month. Do you notice any pattern?
Answer
Mark the new moon and the full moon of three months on the calendar, then look at the gaps.
The pattern: a new moon and the next full moon are about 15 days apart, and the next new moon comes about 15 days after that.
New moon → full moon = about 15 days Full moon → next new moon = about 15 days 15 + 15 = about 30 days → one moon month
Sample answer: In one month you will find one new moon and one full moon, roughly a fortnight apart — for example new moon on 1 and full moon on 16.
Why it happens: The Moon takes about 29 or 30 days to go from one new moon to the next. Half of that time it is growing and half of that time it is shrinking.
Q5.
How are the full moon or new moon days named in your community’s calendar?
Answer
They have their own names, and many festivals are named after them.
The full moon day is called Purnima (Poornima).
The new moon day is called Amavasya.
Sample answer:
Day
Name in the month
What happens
Full moon
Guru Purnima (Ashadh)
teachers are honoured
Full moon
Sharad Purnima (Ashwin)
the brightest autumn moon
Full moon
Kartik Purnima
Guru Nanak Jayanti
New moon
Kartik Amavasya
Diwali
New moon
Mahalaya Amavasya
before Navratri
Tip: In Tamil the full moon is called Pournami and the new moon Amavasai. Ask at home what they are called in your language.