DOT date code (the last 4 digits, e.g. 2319)
The last four digits are the week and year of manufacture: 2319 = week 23 of 2019. The first two digits are the week, the last two the year.
What to do with it
Type the four digits into the date decoder to get the dates of that week and the tyre’s age today. If the side you are looking at ends without them, look at the other sidewall: in the US the full code, with the date, goes on the intended outboard side.
Read the four digits on your tyre: the tyre date decoder →
- What it looks like
- Four digits at the very end of the code that starts DOT, often in a small oval or box of their own near the rim: 2319. On tyres from before 2000, three digits.
- Set by
- 49 CFR 574.5, § 574.5(b)(3) Date code; UN Regulation No. 30, paragraph 3.1.9 and its footnote 4; 49 CFR 571.139, S5.5.1(b)
In detail
- US rule (49 CFR 574.5(b)(3)): week 01 is the first full calendar week of the year, Sunday to Saturday. Its own example: 0109 is the week of Sunday 4 January to Saturday 10 January 2009. So 2319 is 9–15 June 2019.
- UN R30 (3.1.9) asks for the same four digits, week then year, and its footnote allowed three digits before 1 January 2000 — week plus the last digit of the year. A three-digit code means a tyre from the 1990s or earlier.
- The date code is the last group of the tyre identification number; the groups before it name the factory and the tyre, and have their own page.
- The regulations say what the digits mean, not how old is too old. UN R30 and 49 CFR 574.5 set no age limit for a tyre.
What it does not mean
The date code is not an expiry date or a best-before date, and it is not the date the tyre was sold or fitted.
Markings that go with it
Sources
Each document was fetched and read on the date shown; the clause is the one that sets this marking.
- US National Highway Traffic Safety Administration, on eCFR: 49 CFR 574.5 — Tire identification requirements — § 574.5(b)(3) Date code: “The first and second symbols of the date code must identify the week of the year … The third and fourth symbols … the last two digits of the year of manufacture. For example, 0109 means the tire was manufactured in the first full calendar week of 2009.” Checked 2026-09-28.
- UNECE, as published in the Official Journal of the EU: UN Regulation No. 30 — Uniform provisions concerning the approval of pneumatic tyres for motor vehicles and their trailers, Revision 3 (OJ L 201, 30.7.2008) — paragraph 3.1.9 and its footnote 4: “The date of manufacture in the form of a group of four digits, the first two showing the week and the last two the year of manufacture”; “Before 1 January 2000, the date of manufacture may be indicated by a group of three digits”. Checked 2026-09-28.
- US National Highway Traffic Safety Administration, on eCFR: 49 CFR 571.139 — Standard No. 139, New pneumatic radial tires for light vehicles — S5.5.1(b): Since 1 September 2009 the full TIN goes on the intended outboard sidewall; the other side may carry a partial TIN “except for the date code”. Checked 2026-09-28.