Earlier quoted context omitted.
Per day? So around one to three years for the delivery of 150 000 cars.
Per month. But given how much faster they are with the other models and how bad their estimates have been for the Model 3, it just means we don't know how many vehicles they will average per day this year.
The "old" Tesla factory was bought from a joint GM-Toyota venture that achieved average production of 25 000 vehicles per month running those lines for 25 years. Then that venture failed, Tesla bought the factory and repurposed the existing infrastructure.
It's like if SpaceX started by buying an old working NASA rocket design and repurposed it for the Falcon, but for Falcon Heavy they started entirely from scratch developing rocket fuels, engines, materials etc. without ever having done so before.