Funeral services will move from Jersey Crematorium to the Royal Jersey Showground on 1 September.
Multi-faith and non-religious funeral services are being temporarily relocated so that building work can start on the new hospital at Overdale.
The government announced the arrangement last December, initially saying the move would happen in spring 2025.
Officials have now confirmed the relocation will commence on 1 September.
The RJA&HS Members' Room can hold up to 100 people, is accessible, and has 50 parking spaces.
The decision was taken so that services can continue to be conducted 'with dignity and respect' during the construction work at Westmount.
Health Minister Tom Binet says this has been a key priority throughout the planning of the new Acute Hospital.
"The relocation of services to the RJA&HS site allows us to maintain that dignity once construction starts at Overdale in the months ahead, given the very close proximity of the crematorium to the building site."
The Garden of Remembrance will remain open to islanders, and people will still be able to visit the Crematorium's offices.
Infrastructure Minister Constable Andy Jehan has thanked crematorium staff, the Crematorium User Group, and the RJA&HS for their collaboration.
"I would like to emphasise that, while the service aspect of the funeral proceedings will be temporarily relocated, interments, cremations and the use of the Garden of Remembrance will remain at the existing Westmount location."
Some minor works are being done to the Members' Room to prepare it for its temporary use as a chapel for funerals, though it has already been used for larger services.

Nude Dunes available to rent as a shop or commercial unit
Alternative Christmas market encourages gifting art
Neil MacRae returns to Jersey Cricket as Director
Soups and Santas raise £32k for Jersey charities
Guernsey's former Chief Minister resigns as deputy after admitting making indecent images of children
Alcohol licensing law overhaul to go to Jersey's States for approval
LibertyBus replaces 22 buses in its fleet
The Shelter Trust Soup Kitchen returns with 41 flavours