~ (tilde)
character optionally followed by a username, it is replaced by the
current or specified user's home directory.
ACCESSCREATEWRITEyyyy-mm-dd hh:mm:ss,
or -1 to indicate that the timestamp is unavailable
or could not be retrieved.
File methods
lastAccessed (Attribute) and
lastModified (Attribute), and
Rexxutil SysSetFileDateTime.
say SysGetFileDateTime(".") -- (e. g.) 2020-04-01 17:45:20
say SysGetFileDateTime("main.c", "w") -- (e. g.) 2020-02-11 05:00:00