Zero Shadow day
“I thought the most beautiful thing in the world must be shadow.” - Sylvia Plath, The Bell Jar
The lack of shadow is beautiful too. And it happens twice a year, for places between +23.5 and -23.5 degrees latitude. The Sun is almost never exactly overhead at noon, but usually transits a bit lower in altitude, a bit to the north or a bit to the south. We have all studied in school that the Earth's rotation axis is inclined at 23.5 degrees to the plane of its revolution around the Sun, which is why we have seasons. This also means that the Sun, in its highest point of the day, will move from 23.5 degrees south of the celestial equator to 23.5 degrees north of the equator (Uttarayan), and back again (Dakshinayan), in a year. Of course, the northern most and southern most points are the two solstices, and the crossing of the Sun across the equator are the two equinoxes.
For people living between +23.5 and -23.5 degrees latitude, the Sun's declination will be equal to their latitude twice - once during Uttarayan and once during Dakshinayan. On these two days, the Sun will be exactly overhead at noon and will not cast a shadow of an object on the ground. This Zero Shadow Day will clearly be different for different places on earth.
Scroll down below to find your local ZSD, state-wise maps, resource material, and public ZSD events.
An Android App
You can now download an android app for your phone that was created for our Zero Shadow Day campaign.
The app will tell you the ZSD and local noon for your location or any other place, lets you interactively explore the length of shadows and the position of the Sun for any date, time and place, and also have animations that will help you understand and teach others about the ZSD. The app is coming soon in Tamil, Malayalam, Kannada, Telugu, Marathi and Hindi!
This app was made for ASI POEC by Alok Mandavgane.
When is Zero Shadow Day at your location?
Scroll down to find the nearest place to your location
ZSD | Places |
---|---|
6 Apr & 5 Sep | Indira Point |
10 Apr & 1 Sep | Kanyakumari, Nagercoil, Kudankulam, Trinket Island |
11 Apr & 31 Aug | Kovalam, Trivandrum, Kazhakoottam, Nedumangadu, Sathankulam, Tiruchendur |
12 Apr & 30 Aug | Varkala, Ponmudai, Paravur, Kollam, Kottarakara, Punalur, Tenkasi, Tirunelveli, Thoothukudi, |
13 Apr & 29 Aug | Kayankulam, Adoor, Thiruvalla, SankaranKoil, Kovilpatti, Rameshwaram, Ramanathapuram, Car Nicobar |
14 Apr & 28 Aug | Alappuzha, Kottayam, Vaikom, Pala, Sabarimala, Cumbum, Rajapalayam, Sivakasi, Virudhunagar, Paramakudi |
15 Apr & 27 Aug | Kochi, Vypin, Thodupuzha, Idukki, Munnar, Theni, Andipatti, Tirumangalam, Madurai, Sivaganga, Karaikudi |
16 Apr & 26 Aug | Paravur, Aluvag, Chalakudy, Valparai, Kodaikanal, Dindigul, Pudukottai, Pattukottai, Vedaranyam |
17 Apr & 25 Aug | Guruvayur, Ponnani, Thrissur, Ottapalam, Palakkad, Pollachi, Mettupalayam, Udumalpet, Palani, Trichy, Thanjavur, Thiruvarur, Nagapattinam, Little Andaman |
18 Apr & 24 Aug | Kottakal, Malappuram, Coimbatore, Gudalur, Palladam, Tiruppur, Kangayam, Karur, Kumbakonam, Mayiladuthurai, Karaikal, Poompuhar |
19 Apr & 23 Aug | Kozhikode, Koyilandy, Thamarassery, Ooty, Kotagiri, Avinashi, Erode, Tiruchengode, Namakkal, Sirkazhi, Chidambaram |
20 Apr & 22 Aug | Vadakara, Mahe, Thalassery, Perambra, Wayanad, Mudumalai, Bhavani, Mettur, Salem, Kallakuruchi, Neyveli, Panruti, Cuddalore, Port Blair |
21 Apr & 21 Aug | Kannur, Payyanur, Taliparamba, Dharmapuri, Sankarapuram, Villupuram, Pondicherry, Havelock Island |
22 Apr & 20 Aug | Kanhangad, Kasargod, Madikeri, Mysore, Srirangapatna, Shuivanasamudra, Chengam, Tiruvannamalai, Tindivanam, Long Island |
23 Apr & 19 Aug | Uppala Gate, Puttur, Arakalagud, Krishnarajapete, Melkote, Mandya, Channapatna, Ramanagara, Attibele, Hosur, Krishnagiri, Tirupattur, Vanaiyambadi, Kavalur, Ambur, Arani, Kanchipuram, Chengalpattu, Mahabalipuram, Kelambakkam |
24 Apr & 18 Aug | Mangalore, Mooadbidri, Bantwal, Sakleshpur, Hassan, Shravanabelagola, Bidadi, Bangaluru, Dasarahalli, Bangarapet, Kolar, Gudiyattam, Vellore, Arcot, Arakkonam, Sriperumbudur, Tiruvallur, Avadi, Chennai, Interview Island, Sound Island |
25 Apr & 17 Aug | Udupi, Brahmavar, Karkala, Sringeri, Kudremukha, Chickmagaluru, Halebeedu, Arsikere, Tiptur, Tumkur, Doddaballapura, Chickballapura, Chintamani, Chittoor, Thiruthani, Minjur, Pulicat, North Andaman |
26 Apr & 16 Aug | Kundapura, Trasi, Thirthahalli, Kuppali, Kadur, Tarikere, Sira, Gauribidanur, Peddur, Madanapalle, Tirupati, Srikalahasti, Sriharikota |
27 Apr & 15 Aug | Bhatkal, Muthala, Shivamogga, Channagiri, Hiriyur, Madakasira, Rayachoty |
28 Apr & 14 Aug | Honnavar, Kumta, Jog Falls, Shikaripur, Challakere, Kadiri, Nellore |
29 Apr & 13 Aug | Kumta, Gokarna Sirsi, Ranebennur, Davangere, Anantapur, Cuddapah, Ramathirtham |
30 Apr & 12 Aug | Karwar, AgondBa, Haveri, Kudigi, Tadipatri. Jammalamadugu, Proddatur, Kavali |
1 May & 11 Aug | Benaulim, Margao, Dandeli, Hubli, Hospet, Bellary, Guntakal, Gooty |
2 May & 10 Aug | Panjim. Vasco, Anjuna, Dharwad, Gadag, Gangavathi, Nandyal, Ongole |
3 May & 9 Aug | Sawantwadi, Belgaum, Sindhanur, Kurnool, Markapur, Chirala, Bapatla |
4 May & 8 Aug | Malvan, Gokak, Bagalkot, Vinukonda, Chilakaluripet, Machilipatnam |
5 May & 7 Aug | Devgad, Radhanagari, Mudhol, Raichur, Deosugur, Narasaraopet, Guntur, Mangalagiri, Gudivada |
6 May & 6 Aug | Ambolgad, Kolhapur, Ichalkaranji, Yadgir, Mahbubnagar, Vijayawada, Eluru, Bhimavaram, Tanuku |
7 May & 5 Aug | Ratnagiri, Sangli, Miraj, Vijayapura, Nalgonda, Nuzividu, Tadepalligudam, Rajahmundry, Kakinada |
8 May & 4 Aug | Jaigad, Karad, Afzalpur, Kalburgi, Suryapet, Khammam, Samarlakota |
9 May & 3 Aug | Chiplun, Mandrup, Akkalkot, Hyderabad, Secunderabad, Kothagudam |
10 May & 2 Aug | Satara, Pandharpur, Solapur, Basavakalyan, Sangareddy, Jangaon, Palwancha, Visakhapatnam |
11 May & 1 Aug | Mahabaleshwar, Phaltan, Tuljapur, Medak, Warangal, Vizianagaram |
12 May & 31 Jul | Mangaon, Baramati, Barshi, Osmanabad, Ausa, Nariapur, Malkangiri, Srikakulam |
13 May & 30 Jul | Mulshi, Pune, Daund, Latur, Karimnagar, Pamunuru, Sukma, Salur, Bobili |
14 May & 29 Jul | Alibaug, Lonavla, Talegaon Dabhade, Pimpri Chichwad, Dehu Road, Jamkhed, Ambajogai, Nizamabad, Korutla, Ramagundam, Palakonda |
15 May & 28 Jul | Mumbai, Navi Mumbai, Karjat, Matheran, Rajgurunagar, Manchar, Ralegan-Siddhi, Beed, Gangakhed, Mancherial, Mandamarri, Dantewada, Jagdalpur, Jeypore |
16 May & 27 Jul | Borivali, Thane, Dombivili, Kalyan, Bhiwandi, Badlapur, Narayangaon, Khodad, Ahmednagar, Parbhani, Nanded, Nirmal, Mamda, Dudme, Bastar, Nowrangpur, Rayagada, Taptapani, Brahmapur |
17 May & 26 Jul | Nala Sopara, Virar, Asangaon, Basmat, Kouta, Aheri, Chhota Dongar, Mahulpatna, Pattapur, Ganjam |
18 May & 25 Jul | Palghar, Kasara Budruk, Sangamner, Shrirampur, Ambad, Hingoli, Adilabad, Mulchera, Koksara, Satapada |
19 May & 24 Jul | Dahanu, Nashik, Kopargaon, Vaijapur, Aurangabad, Jalna, Pusad, Balharshah, Rowghat, Dharmagarh, Bhawanipatna, Bellaguntha, Puri |
20 May & 23 Jul | Talasari, Takh, Mehkar, Washim, Wani, Chandrapur, Mul, Keskal, Nayagarh, Motari, Saharabedi |
21 May & 22 Jul | Bilad, Silvassa, Khedgaon, Manmad, Kannad, Chikhli, Rohna, Wadki, Bhanupratappur, Kanker, Kusuruparaha, Bhubaneswar, Paradeep |
22 May & 21 Jul | Daman, Vapi, Malegaon, Chalisgaon, Buldana, Khopadi, Yavatmal, Armori, Charama, Saintala, Phulbani, Cuttack |
23 May & 20 Jul | Diu, Valsad, Bhadgaon, Khamgaon, Akola, Wardha, Kusumkasa, Dhamtari, Balangir, Dhenkanal, Bharcchan |
24 May & 19 Jul | Somnath, Jafarabad, Navsari, Amalsad, Dhule, Jamner, Shegaon, Nimbora, Wardha, Umred, Kurud, Nuapada, Angul, Bhuban, Jajpur |
25 May & 18 Jul | Mangrol, Talala, Rajula, Mahuva, Vadoli, Sakri, Amalner, Jalgaon, Bhusawal, Telhara, Amravati, Rajnandgaon, Nawapara Nagar, Padmapur, Bhadrak |
26 May & 17 Jul | Madhavpur, Datha, Surat, Bardoli, Vyara, Nardana, Chopda, Paratwada, Nagpur, Durg, Bhilai, Bhandara, DOngargarh, Raipur, Barpali, Markona |
27 May & 16 Jul | Keshod, Savar Kundla, Alang, Nandurbar, Shirpur, Burhanpur, Tumsar, Gondia, Katapali, Chandipur |
28 May & 15 Jul | Junagadh, Paltana, Ankleshwar, Shahada, Pandhurna, Tilda, Sambalpur, Balasore |
29 May & 14 Jul | Porbandar, Upleta, Amreli, Bhavnagar, Bharuch, Sendhwa, Chichanda, Bhatapara, Jogal, Digha, Mousuni |
30 May & 13 Jul | Ghumli, Jamkandorana, Rajpipla, Khargone, Khandwa, Betul, Balaghat, Raigarh, Jharsuguda, Banei, Contai, Pathar Pratima Island |
31 May & 12 Jul | Bhogat, Bhanvad, Gondal, Gadhada, Amod, Nasvadi, Barwani, Birsa, Kawardha, Champa, Joda, Baripada, Nandigram |
1 Jun & 11 Jul | Bhatiya, Kamlapur, Sarangpur, Dabhoi, Kasrawad, Sanawad, Chhindwara, Seoni, Mungeli, Bilaspur, Sundargarh, Barbil, Manda, Beida, Haldia, Devasora South |
2 Jun & 10 Jul | Dwarka, Rajkot, Dholera, Vadodara, Bodeli, Manawar, Sukhtara, Pandaria, Rourkela, Baharagora, Tamluk, Phura |
3 Jun & 9 Jul | Motikhavdi, Dhandhuka, Borsad, Harda, Chhapara, Korna, Banki Mongra, Lailunga, Jorapokhar, Kharagpur, Medinipur, Debra, Baruipur, South Bungtlang, Kawichaw East |
4 Jun & 8 Jul | Jamnagar, Petlad, Tutugutu, Chaibasa, Kokpara, Jhargram, Bagnan, Maheshtala, Mothbari, Siaha |
5 Jun & 7 Jul | Dhrol, Wankaner, Thrangadh, Limbdi, Anand, Mhow, Itarsi, Lakhnadon, Mandla, Pathalgaon, Ghatshila, Howrah, Kolkata, Hasnabad, Chawngte P, Vaumbuk |
6-10 Jun & 6-2 Jul | Gandhidam, Morbi, Surendranagar, Dhrangadhra, Ahmedabad, Nadiad, Godhra, Dahod, Indore, Dewas, Hoshangabad, Narsingpur, Guthurma, Kunkuri, Jamshedpur, Dhaniakhali, Kalyani, Barrackpore, Bomgain, Basirhat, Lunglei, Lungsen |
11-21 Jun & 2 Jul-21 Jun | Kothara, Bhuj, Gandhinagar, Ratlam, Ujjain, Tarana, Bhopal, Jabalpur, Shahpura, Chirimiri, Ambikapur, Surajpur, Ranchi, Balarampur, Purulia, Bankura, Burdwan, Hanshkali, Thenzawl, Serchhip, Zokhawthar |
You can also download this list as a pdf.
Download the ZSD poster here as a pdf.
Download state-wise maps with the ZSDs marked
ZSD Posters pdf files
English | हिन्दी | বাংলা | தமிழ் | ಕನ್ನಡ | ਪੰਜਾਬੀ | অসমীয়া |
Contributors:
Alok Mandavgane, Aryabhat Foundation, Bhopal
Amoghavarsha N, IIA, Bengaluru
Aniket Sule, HBCSE (TIFR), Mumbai
Arvind Paranjpye, Nehru Planetarium, Mumbai
B S Shylaja, Jawaharlal Nehru Planetarium, Bengaluru
Chaitanya Ursekar, HBCSE (TIFR), Mumbai
Chitradeep Saha, CESSI, IISER Kolkata
Chrisphin Karthick, IIA, Bengaluru
Dibyendu Nandi, CESSI, IISER Kolkata
Harvinder Jassal, IISER-M, Mohali
Mamta Gulati, IISER-M, Mohali
Manikandan Sambasivam, IMSc, Chennai
Niruj Mohan Ramanujam, IIA, Bengaluru
Pavan Dharanipragada, IMSc, Chennai
Poran Baruah
Prateek Chawla, IMSc, Chennai
Punith R, IIA, Bengaluru
Rakesh Netha Vadnala, IMSc, Chennai
Satyajeet Sinha
Thiru Senthil, IMSc, Chennai
TV Venkateswaran, Vigyan Prasar, Delhi
Varuni P, IMSc, Chennai
Virendra Yadav, ARIES, Nainital
Yoshita Baruah, CESSI, IISER Kolkata
Resource material on Zero Shadow Day
Articles
Information on the ZSD for Karnataka in Kannada, by the Jawaharlal Nehru Planetarium
An article on the ZSD by R. Kavitha in Tamil
An article on the ZSD by Sanjeev Khudshah in Hindi
An article on the ZSD by Umashankar Mishra in Hindi
An article on the ZSD by Vibhu Mishra in Hindi
An article on the ZSD by Sonal Thorve in Marathi
Presentations
An introduction to ZSD by Rugved Pund of JVP (1.0 MB, English)
An introduction to ZSD by Dr. T.V. Venkateswaran (9.4 MB, English)
An activity guide for ZSD by Dr. T.V. Venkateswaran (0.7 MB, English)
An introduction to positional astronomy by Dr. T.V. Venkateswaran (2.8 MB, English)
An introduction to ZSD by Mr. Madivanane (8.8 MB, English)
Videos
Two videos in Hindi by Alok Mandavgane explaining the theory behind ZSD as well as how we can observe it
Videos
Two videos in Hindi by Alok Mandavgane explaining the theory behind ZSD as well as how we can observe it
More Videos
A video explaining the concept of Zero Shadow Day made by the Arvind Gupta Science Toys group at IUCAA. Pune (in English)
A time-lapse video taken by Arvind Paranjpye in Pune
So informative page about Positional Astronomy.
Now I decided to continue to visit this website ones in a week.
Thanks for the detailed map of no shadow day. If not for this resource it is hard to come by information.
Excellent information! Thanks for sharing!
Thanks a lot Sir
Sir
Please what is date and time of ZSD for Jaipur and for Bikaner?
There wont be any Zero shadow moment in Bikaner. As it lies north to Tropic of Cancer.
Read the article
Very great and very exploring videos I didn’t know that zero shadow day was any thing also thanks very much because of giving all information about the topic
Thanks a lot Sir for your Encouragement to observe the Zero Shadow Day Program on 23rd May at Chimnibhati para,Balangir of State Odisha.
Regards
Ananda Barpanda, District Coordinator
Children’s Science Congress of Balangir DIST Odisha
Please put about space
Please can we have the dates for the year 2018?
Is the ZSD date doesn’t change for one location?
What if we have leap year.. will it come a day before on our calendar?
Nice Article and information ! Thanks !!
Informative material for all willing to enhance the knowledge
thanks a lot for this information….
this information is very very interesting…..
Thank you for the detailed information. I am thankful to Sri Panditharadhya Sir from Maisuru who informed me about this event.
Your App dates for ZSD is different from the dates displayed in this webpage. For the any places. Please can you tell me correct ZSD for (1) GUDIVADA KRISHNA DISTRICT ANDHRAPRADESH
(2) Machilipatnam Andhrapradesh
(3) Vijayawada Andhrapradesh.
Thank you for this article. I have linked it on my blog for the wonderful piece of information.
I will right away clutch your rss as I can’t find your email subscription hyperlink or e-newsletter service.
Do you have any? Please let me know so that I may just subscribe.
Thanks.
Thank you for the detailed and breif information. It add up my knowledge .. and i am thankful to pravin sir who told us about it … it is very helpful .
Thank you for the detailed and breif information. It add up my knowledge .. and i am thankful to pravin sir who told us about it … it is very helpful .
Good effort to educate young people.
best!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
This website is single destination to learn about ZSD: Learned a lot from here.
So its time to give back with some useful content…
We have launched Space Time YouTube channel dedicated for quality Astronomy educational content in English and Telugu and aiming for more regional languages soon with the help of volunteers:
The first video is on Zero Shadow day and how it happens…
English:
https://www.youtube.com/watch?v=BOPsuuPo_zE&t=5s
Telugu:
https://www.youtube.com/watch?v=VEN7XNsiRG4&t=5s