since

Evaluates as true if the specified time property of the file is greater than the since value. Note that this is not the same as the since generator; when used as an expression term we are performing a straight clockspec comparison. When used as a generator, candidate files are selected based on the since time index. The end result might or might not be the same--in particular, if the since time index is not passed in, it will be treated the same as a fresh instance, and only files that exist will be returned. The efficiency can vary based on the size and shape of the file tree that you are watching; it may be cheaper to generate the candidate set of files by suffix and then check the modification time if many files were changed since your last query.

This will yield a true value if the observed change time is more recent than the specified clockspec (this is equivalent to specifying "oclock" as the third parameter):

 ["since", "c:12345:234"]

You may specify particular fields from the filesystem metadata. In this case your clockspec should be a unix time value:

 ["since", 12345668, "mtime"]
 ["since", 12345668, "ctime"]

You may explicitly request the observed clock values too; in these cases we'll accept either a timestamp or a clock value. The oclock is the last observed change clock value (observed clock) and the cclock is the clock value where we first observed the file come into existence (created clock):

 ["since", 12345668, "oclock"]
 ["since", "c:1234:123", "oclock"]
 ["since", 12345668, "cclock"]
 ["since", "c:1234:2342", "cclock"]