HOME SETUP TIMER
How long does a Casper Snow mattress take to fully expand?
Quick answer
Use 72 hours as the starting point.
After unboxing
Start a reminder timer
72 hours
Timer has not started.
When it rings: Check the full height and corners after the expansion window.
What the source actually says
Casper says Snow mattresses can take up to 72 hours to expand fully.
Expansion time and sleep-ready time are not necessarily the same claim.
Source
Read the manufacturer guidance. Model instructions override this general page.