I made a keystore a while ago for my Android apps but I can't remember how long I set the validity for.
Is there a way to find out how long the keystore is good for?
You can use the keytool from the jdk to get certificate info. A command like this should work
keytool -list -v -keystore keystore.jks -alias mydomain
Replace
'keystore.jks' with your keystore name
'mydomain' with your alias name