NEW DELHI -- Three weeks, 29 questions and more than a billion heads to count.
India is busily conducting its 15th national census, with millions of government workers deploying across the country to tally its estimated 1.17 billion people and ask questions on housing, work and education that should give a clearer picture of the world's most populous democracy and its vast needs.
It's a monumental effort. The census workers - most of them school teachers armed with clipboards and computer surveys - are out negotiating skyscrapers, navigating farm roads and forest paths, visiting village huts and knocking on slum doors to find everyone they can before the census deadline of March 1. Anyone older than 15 must be questioned.
"There is so little time," one census worker said, tapping his temple. "This mind will bifurcate in two pieces! But it is the national work. It must be done."
And this year, following a decade of liberalization and unprecedented economic growth, there is an eagerness among many citizens to participate. They know the 10-year census may help authorities identify areas where neglect is high, where poverty is particularly rife and where high numbers of people are unable to read or to work.
"It can lead to help for the poor and maybe help establish some reforms," said 16-year-old Jatin Anand, who excitedly signed off on his first census survey in the cramped New Delhi neighborhood of Baljeet Nagar.
His mother, Meena, agreed. "We also come to know about the children ... their education, services," she said.
This is the second census phase, with the first last year listing some 300 million Indian households. Baljeet Nagar holds some 7,000 of those homes, many no wider than their front door and divided by narrow alleys strewn with garlands of laundry lines and loose electrical wires.
Former army soldier Hira Lal, sitting on the broken concrete steps of his modest home, said he hoped the census would lead to better benefits. "The way inflation is going, maybe they will see a need to raise pensions," the 67-year-old Lal said.
Meanwhile, 41-year-old Geeta Ajmatkhan, who fully considers herself a Delhiite after 21 years in the capital, hopes the demographic information prompts more social control for cities overwhelmed by a constant influx of migrant workers.
"The census is a good way of finding out who has been staying in Delhi, who is coming from outside and who is creating a nuisance," Ajmatkhan said.
There are 89 teachers assigned to canvass Baljeet Nagar, and for the first time they will be considering that women may be the heads of their households, rather than just men.
"It makes me happy to participate and be counted as part of the country," said Veena Suri, 47, smiling as she tossed the end of her woolen shawl over her thick shoulder.
The census now asks for actual birth dates, to avoid respondents giving only approximate ages. If someone can remember only that they were born, say, during a certain festival in 1934, it's up to the census worker to find out what date that is.
For the first time, the census is noting whether people live in mud huts or concrete structures, have electricity or access to toilets and if they have ever been to school even if they don't go anymore - key questions for a country with some 800 million people living in poverty.
The millions of homeless sleeping on railway platforms, under bridges and in parks will be last counted on the evening of Feb. 28, with revisions conducted until March 5 and the final census reports published over the next two years.
"There's a very wide range of socio-economic data being collected," touching on literacy and education levels, work and fertility, marriage and migration, New Delhi census director Varsha Joshi said. There are 15 official languages apart from English to note, and myriad religions represented. New categories for disability and "third-gender" are part of an effort to make the count more accurate and culturally relevant.
"All these together ... They give a complete social picture of the country," Joshi said.
The disabled now have eight categories to qualify their condition. Prostitutes will be listed as having "other" employment rather than as "beggars."
The transgender community, which has long hoped for more social acceptance, is being given an "other" option under gender apart from "male" and "female." The results will give India a firm count for its "third-gender" hijra community - the origins of which go back millennia to a time when transsexuals, eunuchs and gays held a special place in society backed by Hindu myths of their power to grant fertility. Today, transsexuals are subjected to harsh discrimination in housing, employment and society, though last year they were granted their request to register to vote as "others."
Having a third-gender option in the census "was a demand from the community," Joshi said. "They wanted their numbers to be counted."
India's president, the government, religious leaders and NGOs for the homeless and disabled have all urged people to stand and be counted so their needs might be better met.
Officials are even counting foreigners including sailors docked in Indian ports and inmates locked up at Indian prisons such as Pakistani Ajmal Kasab, who is sentenced to death for his role in the 2008 Mumbai terror attacks.
But there are some who won't make the roster - the children of unwed mothers.
Authorities deemed it too culturally insensitive to have their census workers ask unmarried women if they have kids - a situation rare enough, they say, to be numerically insignificant. In India, arranged marriage is still largely the norm, and nearly 45 percent of girls are married by the time they're 18, according to the last census in 2001.
Another topic deemed too sensitive for this year's census was that of caste, which will be surveyed separately later this year as officials try to understand how deeply society still reflects the millennia-old Hindu custom dividing people in a strict social hierarchy based on their family's traditional livelihood and ethnicity.
Census officials worried the sensitive subject of caste in multicultural and secular India could upset the results of the population count.