Again, valid means valid to CIC not to your currently. The definition of valid means:
If you need a police certificate from a country or territory and:
- are currently living there, or received the police certificate before leaving, the police certificate must be issued within six months before you apply.
- have lived there in the past, the police certificate must be issued after you last lived in that country or territory.
That is, take these two scenarios for your current country of residence:
1- Your PCC has one month expiry date but is issued within 6 months of application date -> It is valid.
2- Your PCC has one year expiry date but is issued 7 months before application date -> It is NOT valid.