The U.S. government got another week older and about $15 billion deeper in hock this week, bringing the national debt above $990 billion and setting the stage for a quick ascent to the landmark level of $1,000,000,000,000.

Treasury Department officials say they cannot predict the date when the milestone will be reached. But thousands of Washington Post readers have tried to outsmart the experts by entering the Federal Report's Trillion-Dollar Forecast. The genius who wins will be featured on this page, treated to a lunch on The Post and favored with a Washington Post book bag stuffed with Post T-shirts for the winner's whole family.

You can enter by filling out the entry blank below, or any reasonable facsimile, telling us what day the debt will top $1 trillion, and how large the debt will be (to the nearest million dollars) at the close of business on that historic day. Everyone is eligible except Washington Post and Treasury Department employes.

The debt closed at $981.207 billion on Sept. 29. Yesterday the total went up by at least $13 billion as the Treasury issued new securities to the Civil Service retirement fund. Next Thursday, Treasury plans to issue securities adding another $9 billion to the total. The government also probably will redeem some securities next week, which would reduce the debt total.

The trillion-dollar debt is imminent. If you can predict the banner day, you could win the Trillion-Dollar Forecast contest.