Current year (at the time the program is being run).

Find year for a clj-time time (Joda DateTime).

Get “update” date and time in milliseconds for a file on the file system.

Useful links: https://github.com/juxt/yada/blob/master/src/yada/resources/file_resource.clj http://stackoverflow.com/questions/2723838/
determine-file-creation-date-in-java

Find Joda DateTime for an Org post in HTML format, first looking in the Org Mode header, and if not present there, using the filesystem time.