.dev0 just means it’s not a release. i.e. not reliable.
The date would be useless because 20181025 in one part of the world will not be 20181025 in another, so it’s not a good reference point. If you need to rely on an exact time stamp, you can always use git tools to see when the last commit was made in the fastai repo of your checkout.
Unless you meant 1.0.14.20181025 (no dev in your example), then your question is of a different nature.