The elderly can report to the public security organ at any time when they are lost. There is no time limit for this.
 1、 If a person is lost, he or she can report the missing person to the local police station where the missing person's household registration is located or to the public security organ in the missing place according to the circumstances. After accepting the case, the public security organ shall decide whether to file the case according to the investigation. However, in general, if an adult has disappeared for more than 24 hours, the immediate family members of the disappeared person can report the case to the local police station with their own identity documents and the supporting documents of the missing person's relationship, and provide relevant information.
 2、 The following circumstances may be reported to the public security organ at any time:
 1. If there is evidence proving that the other party may be in danger of personal safety, or that the other party may be infringed, the case can be reported to the public security organ at any time;
 2. The missing person is a mentally ill person with no or limited capacity for civil conduct or a person with intellectual disability who can report to the public security organ at any time;
 3. In case of missing persons due to an accident, the party involved in the accident shall report to the public security organ at any time.
 3、 Any unit or individual who discovers that there are criminal facts or criminal suspects has the right and obligation to report the case or report it to the public security organ, the People's Procuratorate or the People's Court.
 [Legal Basis]
 Article 175 of the Provisions on the Procedure of Public Security Organs in Handling Criminal Cases: After examination, if a case is found to have criminal facts but not under their own jurisdiction, it shall be immediately reported to the person in charge of the public security organ at or above the county level for approval, a notice of case transfer shall be made, and the case shall be transferred to the organ with jurisdiction within 24 hours, and the person who seized the case, the person who reported the case, the complainant Informants. If it is not under its jurisdiction but it is necessary to take emergency measures, it shall first take emergency measures, then go through the formalities and transfer them to the competent authority.
 If a matter that does not fall within the scope of the public security organ's duties can be judged on the spot when receiving a report, the person who seized the case, the person who reported the case, the complainant and the informant shall immediately be informed orally to report the case to other competent authorities.
 If a case is repeatedly reported, is being handled or has been completed, an explanation shall be given to the person who seized the case, the person who reported the case, the complainant or the informant, and no registration shall be made, except where there are new facts or evidence.