Schilt was born in 1894 in the Netherlands, and educated there under Jacobus Kapteyn. He emigrated to the United States in 1933 as the Chair of Columbia University's astronomy department, a position which he filled until his retirement in 1962, when he was granted the title of Rutherford Professor of Astronomy Emeritus.
Schilt's astronomical work included the invention of the Schilt photometer, a device which measures the light output of stars, and, indirectly, their distances. He worked on the motions of star streams in the Milky Way Galaxy, and was director of the Yale-Columbia Southern Station in Johannesburg and Canberra, as well as Director of the Rutherford Observatory at Columbia.
Schilt was noted at Columbia for walking into his classes the first day after the launch of Sputnik 1 and commenting "Well, gentlemen, it is not every day we have something new in the sky to talk about", following which he devoted the entire class to proving that Sputnik had been deliberately launched into an orbit designed to make it invisible from the United States for as long as possible (six weeks).
He died in New Jersey in January 1982.
13,500 items of his papers are contained in the Rare Book and Manuscript Library of Columbia University.
Published works 
- Barney, Ida; Schilt, Jan (1927). "Discussion of the proper motions in the equatorial Zone". Astronomical Journal 37.
- Barney, Ida; Schilt, Jan (1930). "Analysis of the Yale proper motions in the zones between +50 degrees and +55 degrees and between +55 degrees and +60". Astronomical Journal 40.
See also 
- New York Times obituary, January 11, 1982
- Columbia University Library Bulletin