Leitao's office confirmed the date of the budget in a news release Monday.
The rookie finance minister says the transitional budget will serve to redress public finances while reviving the economy.
Leitao said he didn't want to rush the auditor general.
"What we want his report for is to verify the expense figures because the revenues were done in February," he said, adding the report wouldn't change the budget itself but could affect the "tone."
Treasury Board president Martin Coiteux will table the spending estimates for 2014-2015 the same day as the budget.
He said in a statement the estimates would attest to the "rigour" and "responsibility" Quebecers expect in the management of their public finances.
Premier Philippe Couillard has warned since taking power that the time has come for hard economic decisions.
The Liberals have aimed to meet the previous Parti Quebecois government's objective of a $1.75-billion deficit in 2014-15 and a balanced budget the following year.
The government has already brought in a hiring freeze in the public sector and is doing a complete review of its programs and services.
The Liberals were elected with a strong majority on April 7, winning 70 of the 125 seats in the legislature.