Count down until a certain value is reached

[tkkaze]

Hi everyone,

I'm looking for a formula to count down until it finds a certain value, which will return zero.

For example:

Demand	52	12	0	32	15	19	0
Demand until zero	2	1	0	3	2	1	0

...in which the formula is in the "Demand until zero" row.

I've attached a file that I hope can help detail my question further.

Thanks in advance!