since

$ watchman since /path/to/dir <clockspec> [patterns]

Finds all files that were modified since the specified clockspec that match the optional list of patterns. If no patterns are specified, all modified files are returned.

The response includes a files array, each element of which is an object with fields containing information about the file:

{
    "version": "2.7",
    "is_fresh_instance": true,
    "clock": "c:80616:59",
    "files": [
        {
            "cclock": "c:80616:1",
            "ctime": 1357617635,
            "dev": 16777220,
            "exists": true,
            "gid": 100,
            "ino": 20161390,
            "mode": 33188,
            "mtime": 1357617635,
            "name": "argv.c",
            "nlink": 1,
            "oclock": "c:80616:39",
            "size": 1340,
            "uid": 100
        }
    ]
}

The fields should be largely self-explanatory; they correspond to fields from the underlying struct stat, but a couple need special mention:

• cclock - The "created" clock; the clock value representing the time that this file was first observed, or the clock value where this file changed from deleted to non-deleted state.
• oclock - The "observed" clock; the clock value representing the time that this file was last observed to have changed.
• exists - whether we believe that the file exists on disk or not. If this is false, most of the other fields will be omitted.
• new - this is only set in cases where the file results were generated as part of a time or clock based query, such as the since command. If the cclock value for the file is newer than the time you specified then the file entry is marked as new. This allows you to more easily determine if the file was newly created without having to maintain a lot of state.