One thing is clear: The state constitution requires Gov. Phil Murphy to sign a state budget by midnight on June 30, or face a government shutdown.

What has been made increasingly unclear is just how budget talks will play out these next few months, as the coronavirus outbreak sends shock waves across markets, including some of the worst days Wall Street has seen in decades, and plummeting revenues for virtually every industry in New Jersey.

The stock market – where much of the state’s public worker retirement system is invested – has swung wildly, leading to March 9’s “Black Monday”: Wall Street’s single worst day since 1987.

Large gatherings – concerts, conferences and sporting events – have all been cancelled. Malls, gyms and theaters are closing their doors indefinitely. Bars and restaurants are closing hours earlier than usual as towns enact 10 p.m. curfews. Grocery store shelves are cleared out on a daily basis.

Casinos are cancelling entertainment and face pressure to close their doors. Airports are barren. Ridership on New Jersey Transit’s buses and trains is plummeting. Employees are working from home.

All this economic activity makes up billions of dollars in tax revenue each year for the state budget. Temporary overhauls to the state’s taxation system, in order to provide relief to those businesses, could spell disruptions for that money coming into the state’s coffers.

“We also recognize that the threat of the coronavirus is not just to public health but to our economy as well. The global data is showing us this in very real terms,” Murphy said in a briefing with reporters on March 2.

In February, Murphy rolled out a $40.9 billion spending plan, which calls for $17.8 billion from the state income tax, $10.7 billion from the sales and use tax, and billions of dollars more in hundreds of other taxes and fees. His budget also anticipates $1.5 billion in surplus by June 30 – when the 2020 fiscal year ends – and a $1.7 billion surplus by the end of the 2021 fiscal year.

Constitutionally, the governor has to balance the budget, meaning there cannot be a deficit. When faced with a nearly $1 billion budget shortfall in 2014, then-Gov. Chris Christie, a Republican, took the money from the proposed public worker pension payments in order to plug those holes.

Christie’s predecessor, Democrat Jon Corzine, enacted a one-year millionaire’s tax for the 2010 budget, when faced with shortfalls stemming from the Great Recession.

“As always, Treasury is continuously monitoring the stock market and economic conditions, taking into account any potential impact COVID-19 may have on tax revenues,” State Treasurer Elizabeth Maher Muoio said in a March 13 statement.

Sales tax is measured from month to month, but even then there’s a one-month reporting delay, Muoio said.

“The impact would also be predicated on the length and depth of any change in economic activity,” she said. “We will continue to provide monthly public revenue updates and I will provide detailed revenue updates to the Senate and Assembly budget committees over the next several months.”

The treasurer maintained that the pension is “based on longevity” and “by design” is able to ride out “short-term volatility.”

“Therefore, it’s not prudent to speculate on short-term activity,” Muoio said.

Lawmakers are also putting forward a series of economic relief measures that would enact tax holidays to take the pressure off of businesses. The tax filing deadline is April 15, and the state treasury will appear before lawmakers to unveil just how much money the state will make for the 2020 fiscal year.

When the budget was first introduced, it was built on the projection that revenue collections would remain strong through June 2021.

“There’s no assumption of a financial downturn in the latter half of the fiscal year,” said one senior administration official last month. “Our revenue estimates are based on relatively modest economic growth assumptions, that’s what we baked into our forecast for both this year and next year.”

Still, the Murphy administration has pointed toward market turmoil and economic uncertainty as justification for continuing to put money into the rainy day fund, which under the governor’s plans would clock in at $745 million by June 2021.

“This is another reason why we will remain fiscally responsible to ensure that New Jersey’s financial footing remains sound and based on sound practices, and so we have resources available through both our surplus and the rainy day fund to protect against any economic emergency,” Murphy said last week.