It is on NBCSN, coverage starts at 2:00 p.m. EST tomorrow (1-26-2019), race begins at 2:25 p.m. and ends 24 hours later. Zanardi is driving for the Rahal BMW team in the GTLM class. Other notable drivers in this race are former F1 drivers Fernando Alonso and Reubens Barachello.
FYI
The qualifying lap record was held for 26 years. In 1993, P J Jones, driving a Dan Gurney Toyota Eagle MKIII lapped at a best 1m 33.875s. IMSA changed rules to lower cost/performance so that the US Prototype 1 cars performed similarly to European Prototype 2 cars. But the designers have been increasing performance and this year the Team Joest Mazda Prototype beat the old record by a few tenths of a second.