If you have an hourglass that allows sand to flow through it out into a sandbox at a rate of 1kg per day, yet you actively shovel 2kg per day of sand into it, y

If you have an hourglass that allows sand to flow through it out into a sandbox at a rate of 1kg per day, yet you actively shovel 2kg per day of sand into it, you are going to be accumulating 1kg of sand per day in your hourglass. Regardless of the fact that the sand will eventually all flow back out into the sandbox over a long enough timeline.