Planned visits to "unsheltered outdoor locations where homeless people are known to spend the night - under bridges, near buildings, in the woods" has been pushed back one day to tonight, Gallagher said.
A bureau spokesman said the homeless are part of the bureau's effort to try to count everyone in the nation and would not become a separate category.
"This is not an easy operation," he said. "It's very difficult, even after we find these folks living in these conditions" because some don't want to cooperate.
Operators of shelters and soup kitchens say they have notified their clients that census workers are coming and told them that being counted helps direct federal aid for programs in the community.
Jean Kelly, executive director of Hempstead-based Interfaith Nutrition Network, which runs several soup kitchens and three shelters Islandwide, said the INN does not allow interviews of clients on its property, and Kelly said her staff will be taking a head count and asking for gender and race information. Census staffers stationed outside will ask clients as they leave to fill out more information, Kelly said, and "we'll advise them not to be frightened to participate."