The duration of an earthquake retrofitting project can vary depending on various factors, including the size and complexity of the structure, the extent of retrofitting required, and the availability of resources and professionals. Generally, for a typical residential property, earthquake retrofitting can take anywhere from a few days to a few weeks to complete. More extensive retrofitting projects or larger buildings may take longer. It's essential to consult with a qualified structural engineer or contractor to assess your property's specific needs and timeline accurately.