Rolex Time sand is packed in 30 kg bags. Each bag's content equals 30 days flowing in a standard hourglass. On the 18 pallets, there are 972 bags
weighing 29 160 kg total, an amount of sand that would last for 81 years, which is my -generous- estimation of an average lifestime.
The image in the middle pictures the artist's lifetime already consumed: 39 years.