Zero hour approaches at Apple’s giant zero-shaped building in Cupertino.

Employees will begin moving into the long-awaited sequel to the computer giant’s original campus (now dubbed Apple Park, presumably because the name Apple II was already taken) in April. The sprawling, multi-billion dollar affair designed by Norman Foster was originally slated for a 2015 opening.

Regular South Bay drone enthusiast and videographer Matthew Roberts published an aerial gander at the locale ahead of moving day, revealing office furniture already moved into some buildings, solar panels glittering like a placid sea over rooftops, and personnel transit humming along through campus tunnels.

But it appears that work will continue long after the move-in process (which itself will last most of the rest of the year). With weeks to go before the big day, work continues planting trees, digging the pond in the center of the ring, building the Steve Jobs Theater, and layering yet more solar panels onto rooftops.

(Panels will eventually cover two-thirds of the building’s 750,000 square foot roof.)

The big announcement about the opening seems to have agitated the drones even more than usual, as the number of aerial accounts of building progress uploaded to YouTube noticeably spiked in March. Note how much the completed R&D building in this one resembles a standard Apple Store in this March 23 footage:

It’s a far cry from the very first, rudimentary footage of the site ever uploaded back in September of 2014, when the notion that commercially available drones flying at legal altitudes could snoop on major construction projects quickly and easily had seemingly occurred only to a few.

The company estimates the 2.8 million square foot complex will house 12,000 Apple employees when all is said and done.

The finished ring will be more than a mile in circumference.