Arista serial number date code
There doesn't appear to be any information online about Arista serial numbers containing the date of manufacture. Extreme, Cisco, and APC are examples of ones I have seen well-discussed online.
After analyzing a fleet of ~100 Arista switches I am reasonably certain that the date is in the serial number in a manner quite similar to these other manufacturers. Let's look at an example from ebay: WTW23100042
| WTW | These first three characters appear to be a country or facility code. This one says "Made in TAIWAN" elsewhere on the label. Also seen: JMX, JPE, HBG, and SGD. |
| 23 | Last two digits of the year. These ranged from something like 18 to 25 in my data set which makes sense in that environment. |
| 10 | Week of the year. I have never seen these two digits higher than 53. |
| 0042 | Probably a number that increments for each one they produce in that facility in that week. I have also seen letters in this part on some models--it appears that in 2023 they switched to this non-decimal encoding. |