[semlar]

I am very confused about what you're trying to do.

I thought you wanted to know how much time before conflagrate was usable again after it hit 0 charges, but you don't need to know the timestamp of when it hit 0 charges for that.

The main reason for knowing when it hit 0 would be to determine when the second charge is going to come back.

I guess the other reason would be if you needed the start time for a cooldown spinner or something.

If you know when it went on cooldown then you know when it hit 0 charges. The most efficient way to determine that really depends on how this is being implemented.

If this is for an action button there are much simpler ways to get the cooldown information.