The physical install is usually 1–3 days; the full process including approvals and meter change can take a few weeks.
The rooftop installation itself — mounting, panels, inverter and wiring — usually takes 1 to 3 days for a typical home, depending on system size and roof complexity.
The full journey is longer than just the install day. It includes a site survey and design, ordering equipment, the physical installation, and then inspection, grid approval and the net-meter change, which depend on your utility.
End to end, expect a few weeks from signing to switch-on, with most of that time spent on paperwork and utility approvals rather than the installation itself.
This is general guidance — figures vary by location, tariff, equipment and installer. Always confirm details for your own home before deciding.