Saturday is the last day for those who use emergency locator beacons to change to new devices.
After midnight, the satellite used to pick up the old 121.5 and 243 megahertz beacons will be switched off.
New 406 megahertz beacons replacing them can send far more information, including contact phone numbers for either the person missing or someone who knows what their plans are.
The Mountain Safety Council says the old beacons are now useless.
