Date-Built, how to find it

Is there somewhere on a cpap machine (Resmed S9) that shows the date it was built? Just curious as to how you know the date.

No, not like on the PR System One machines from Respironics.
About the best you can do is year and where from the serial number.

Example...my S9 serial number is 2214xxxxxx
the 22 denotes where made...there is also a 23....I forget which is what but one is Australia and one is Singapore
the second 2 digits are for the year made....so for my machine manufacture year of 2014...the rest of the numbers are just ordinary serial numbers and mean nothing.
We have no way to know the month of manufacture but ResMed would know but they won't tell us.
ResMed would know because they would have the records for that particular serial number.

I assume ResMed continued this practice with their AirSense line but I haven't seen anything to confirm or show anything any differently.

Thanks, I thought that might be it. My s/n is 23142184677, so 2014. (On my S9)

It says made in Singapore. so 23= Singapore.

I just checked my Airsense 10, the s/n starts out 2314.

Probably means the same on the AirSense machines.
ResMed has been doing it this way for a long time (before I started therapy anyway).

My ResMed AirSense for Her serial starts with 2214 and it also states "Made in Australia" so it seems that they have continued with the same practice.