Bought my 2018 Fit at the end of November 2018, so I've had it a little over 8 months.

I'm a low mileage driver so it is just now coming up on 3,000 miles which I know is not an especially relevant number for a modern vehicle.

Looking at the car's information sticker, I see that is was manufactured in March of 2018 - about 16 months ago..

Owner's manual says 1 year oil change if you don't reach the 15% oil change alert.

Any thoughts as to whether the one year should start from date of manufacture or date of purchase?

 

Date of purchase. Sitting in a dealers lot does not cause the oil to deteriorate. I did my first oil change just under one year of ownership at about 3500 miles.