v.123 - Tempest: Into the Storm Update Notes

PSA people:

if you exchange your lost WS for shields, the shields will have only a 24-hour duration! so make sure you need to use them!

you can exchange a specific number only (it asked me how many i wanted to retrieve) but i dunno if you can retrieve the rest later, or if it counts you as "rewarded"

How do you know they only last for 24 hours? Is there an expiration date on them?