[Question] Why date is not updated when new version is created? about docker-brew-ubuntu-core

[tianon]

If you check https://partner-images.canonical.com/oci/bionic/, the underlying tarball hasn't actually changed, which is why that date is still the same.

However, if you're looking for something that gives you the exact same bits, then yes, the (content addressable) image digest is the best way to ensure you get exactly the same bytes every time you pull the image.

[pando85]

Now it's totally clear, thank you for your answer.