[keycloak-user] SSO Session Max Lifespan Secret Maximum Value

I was playing with the SSO Session Max Lifespan, and noticed that if I set it to a very large value, like 10000 Days, that I could no longer log in to the realm, but the admin console did not validate the input in any way, so I don't know what the secret maximum value is. 1000 Days seems to be OK. 10000 Days is not. Should I book something in Jira for this?