Short answer. Only after demand, and within a month. A thing held under a pledge created by operation of law may be sold only after demand of the amount owed, and the auction must take place within one month of that demand. If the creditor lets that month pass without just grounds, the debtor may require the thing's return.
What the law says
A thing under a pledge by operation of law may be sold only after demand of the amount for which the thing is retained.
Civil Code, Article 2122 — Sale of a Legal Pledge. Read the full provision →
What the law says
The public auction shall take place within one month after such demand. If, without just grounds, the creditor does not cause the public sale to be held within such period, the debtor may require the return of the thing.
Civil Code, Article 2122 — Sale of a Legal Pledge. Read the full provision →
What a pledge by operation of law is
Some pledges are not created by agreement but arise automatically because the law gives a person a right to retain another's property until a claim is paid. A common example is the person who has repaired or worked on a thing and may keep it until his charges are settled, or others whom the Civil Code allows to hold property as security for what is owed them. These are pledges by operation of law: the right to retain the thing comes from the statute, not from a pledge contract. Article 2122 sets out how such a retained thing may be turned into money, and what happens if the creditor drags his feet.
Sale only after demand
The first requirement is a demand. A thing under a pledge by operation of law may be sold only after demand of the amount for which the thing is retained. The creditor holding the thing cannot simply proceed to sell it; he must first demand payment of the sum for which he is keeping it, giving the debtor the chance to pay and recover his property. Only if that demand goes unsatisfied does the route to a sale open. This mirrors the fairness built into pledges generally — the security exists to secure payment, so the debtor must be squarely asked to pay before his property is sold out from under him.
The one-month deadline and the debtor's remedy
The article then fixes a deadline and arms the debtor if it is missed. The public auction shall take place within one month after such demand. If, without just grounds, the creditor does not cause the public sale to be held within such period, the debtor may require the return of the thing. So the creditor has a month from his demand to hold the auction. If he lets that month lapse without just grounds for the delay, he loses his grip on the security: the debtor may demand the thing back. The provision stops a creditor from retaining the property indefinitely while neither selling it nor letting it go.
What this means in practice
For a debtor whose property is being held under a legal pledge, two dates matter: when the creditor demanded the amount owed, and whether a month has since passed without an auction. If the creditor made his demand and then failed, without just grounds, to hold the public sale within that month, you are entitled to require the return of the thing — the delay forfeits his right to keep it for sale. The underlying debt does not vanish, but the creditor cannot go on retaining the item after missing the deadline. So note the demand and the month that follows it, because they define both the creditor's window to sell and your right to recover the property.