Cruz, 21, is accused of the February 14, 2018 massacre at Marjory Stoneman Douglas High School in Parkland, Florida and faces 17 counts of first-degree murder and 17 counts of attempted murder, reports Efe news.
Circuit Judge Elizabeth Scherer, who last week scheduled the trial for January 27, 2020, on Wednesday denied Cruz's lawyers' request for more time.
"We're going to trial in January," Scherer said.
Cruz's defence has indicated that they do not have enough time to interview the witnesses required.
Cruz has pleaded not guilty, but to avoid the death penalty his lawyers have said that he would admit to the crimes in exchange for a life prison sentence, a proposal rejected by Broward County prosecutor Mike Satz.
The shooting sparked the March For Our Lives movement nationwide, which advocates greater control over the sale of firearms.
In Florida, a law was passed in 2018 that increased the minimum age to acquire a firearm from 18 to 21 years and imposed a three-day waiting period for most gun purchases. Similarly, this year, the state also passed a controversial bill that allows teachers to carry firearms on campus.
Meanwhile, the Florida Senate on Wednesday voted 25-15 to formally remove suspended Broward County Sheriff Scott Israel, whose department faced condemnation for its handling of the Parkland school shooting.
Republican Governor Ron DeSantis signed an executive order in January suspending Israel, a Democrat, accusing him of neglect of duty and incompetence.
Under Florida law, the state Senate is required to either remove or reinstate an official suspended by the governor. By siding with DeSantis, senators rejected the recommendation of a special master appointed by the Senate President that Israel should have been reinstated.
( With inputs from IANS )