Solar charging?

A full charge is a full charge.  By spec, the Instinct solar will show 24d at a full battery.  

The days until discharge will increase all the way to infinity if the solar charge rate exceeds the watches discharge rate. 

The battery at this point is still fully charged and will supply 24d (by specification) of smart watch mode without any additional solar charging inputs.

Hm? all I get is a 14 day USB full charge and maybe 15 days with 2 hours of solar, new watch also; reason I asked was that I was seeing some pics of owners with more than 20 days...

I assume from your question you own a Solar Instinct.  If so, check the setting of your Pulse Ox sensor.  If the sensor is turned on during sleep, the days between charges will be dramatically diminished.

If you own a non-solar Instinct, then 14d at full charge is correct.

I have had it on, guess I'll turn it off and see if it increases battery life, peace of mind that the battery is functioning aa new battery.

Thanks for the info!

it's a solar...

Happy to help.

By the way, there is a forum specifically for the Solar Instinct:

https://forums.garmin.com/outdoor-recreation/outdoor-recreation/f/instinct-solar