SpaceIL is one of at least three customers with spacecraft aboard the flight.
The primary payload is an Indonesian telecommunications satellite called PSN-6, built by sat-building company SSL.
Another undisclosed rider rumored to be a U.S. government satellite.
The SpaceIL lander will orbit Earth three times, raising its orbit until being captured by the Moon’s gravity.
The process will take more than two months, and at the Moon, the lander will make two orbits before landing.
SpaceIL said Elon Musk’s SpaceX firm, whose rockets are set to carry the unmanned probe into space, had informed it of “a delay of a number of weeks to the beginning of 2019.”
SpaceIL stressed that the delay was SpaceX’s decision, noting in a statement that tests on their craft, shaped like a pod and weighing some 585 kilograms (1,300 pounds), were proceeding successfully.
SpaceIL did not give precise dates for the postponed launch and landing.