How Old Is My Item?
Many safety items have manufacture dates hidden in serial numbers, stamped into plastic, or printed in codes that are not immediately obvious. Select your item type below, enter the date code, and we will decode it for you.
Decode a Date
Where to Find the Date Code
Tires
Look for the DOT code on the sidewall. It starts with "DOT" followed by a series of letters and numbers. The last four digits are the date code: the first two are the week, the last two are the year. For example, "2419" means the 24th week of 2019 (June 2019). The DOT code may only appear on one side of the tire.
Smoke Detectors
Remove the detector from the ceiling and look at the back. Most units have a label with the manufacture date in MM/YYYY or MM-YY format. Some manufacturers stamp a "Replace By" date instead.
Car Seats
Check the label on the back or bottom of the car seat shell. Both the manufacture date and expiration date are usually printed there. Some manufacturers also stamp the date into the plastic.
Fire Extinguishers
Look at the bottom of the cylinder for a date stamped into the metal, or check the label on the body. Some units have an inspection tag attached to the handle.
Car Batteries
Look for a sticker on the top or side of the battery. The format varies: some use a letter for the month (A through L) and a digit for the year. Others print the date directly.
Water Heaters
Check the serial number on the rating plate. Most manufacturers encode the date in the first characters: the first two letters represent the month (A=January through L=December), and the next two digits represent the year.
Propane Tanks
Look at the collar (the raised ring around the valve). The manufacture date is stamped in MM-YY format. Requalification dates have an "E" prefix.
Frequently Asked Questions
If you cannot find a date code and do not know when the item was purchased, the safest approach is to replace it. For safety items like smoke detectors, car seats, and fire extinguishers, the cost of replacement is trivial compared to the risk of relying on an item of unknown age. You can also contact the manufacturer with the model number; they may be able to identify the production date from their records.
There is no universal standard for date coding consumer products. Tire date codes are standardized by the DOT, but most other product categories allow manufacturers to choose their own format. This is why finding and interpreting the date can be confusing. Our decoder handles the most common formats for each product type.