Later today, the Republican National Convention will unveil a potent visual reference for voters across the country.  They will erect a national debt clock that constantly updates as the federal government spends money it doesn’t have, a reminder of four straight trillion-dollar-plus deficits under Barack Obama:

Republican National Committee (RNC) Chairman Reince Priebus will introduce a “national debt clock” when he opens the GOP convention in Tampa Fla. on Monday.

The clock, which will be mounted inside the hall at the Tampa Bay Times forum will be activated at 2 p.m. EDT when the GOP meet convenes and count the growth in the nation’s debt during the convention.

“This clock reminds every delegate and every American why we are here in Tampa – because America can and must do better,” said Priebus in a statement. “Every American’s share of the national debt has increased by approximately $16,000 during the current administration.”

“Mitt Romney and Paul Ryan are the right leaders at the right time for America. They will turn this fiscal mess around, get people back to work and set our country on a strong foundation for generations to come,” he added.

The convention debt clock will begin counting at $15.9 trillion.

CNS News does a little calculating, and reports that the next milestone of $16 trillion may arrive Thursday evening — not too long before Romney takes the stage:

The federal government’s debt could hit an unprecedented $16 trillion this week while the Republican Party is holding its national convention in Tampa, Fla. …

At the close of business on Thursday, Aug. 23, according to the U.S. Treasury, the federal government’s debt stood at $15,976,519,029,144.14. That left it $23,480,970,855.86 short of the $16 trillion mark.

So far in this fiscal year (from Oct. 1 through Aug. 23), the debt has grown by an average of $3,616,398,477.40 per calendar day ($1,186,178,700,586.99 divided by 328 days). Were the debt to grow at that pace in the week following last Thursday’s close of $15.976 trillion, it would hit $16 trillion this Thursday–the day Mitt Romney is scheduled to give his speech accepting the Republican presidential nomination.

In real terms, though, this isn’t a linear progression:

However, the debt does not grow in a steady, unbroken daily pace. Instead, it expands and retracts from day to day during the business week depending on the value of the bonds the U.S. Treasury sells and redeems. On a day that the Treasury derives more revenue from selling bonds than it pays out to redeem bonds, the debt increases.

Last Wednesday, for example, the debt actually declined by almost $9.7 billion–from $15,970,134,937,605.00 to $15,960,468,522,111.20—as the Treasury redeemed bonds of greater value than it sold. However, on Thursday, the debt increased by slightly more than $16 billion, ending that day at $15,976,519,029,144.14.

For the purpose of calculation, though, the RNCC debt clock will probably use a linear formula.  According to USA Debt Clock, the current level of national debt is $15.991 trillion, leaving less than $9 billion to go in three days.  With that in mind, it’s possible that the debt clock will spin to $16 trillion early on Thursday.  If that happens, expect the GOP to catch that on video and replay it often on Thursday evening.