1 ton of time (twice) - Serpentine, Sandstone, steel, drip system
Two water clocks installed at This Will Take Time in northern California. Each boulder weighs ~1 ton, and the water system drips at less than a drop per second. The first leg of their installation is until 2021.
2L of time (twice) - Water, rock from Arizona split in half, steel wire, stainless steel, plastic bottles. 30 days
1L of time - Water, rock from Joshua Tree, California, steel wire, cotton thread, plastic bottle. 5 days.
2L of time (once) - Water, marble from VT, steel wire, plastic bottle. 30 days.