Library /sys$common/syshlp/nclhelp.hlb set, dtss, check_interval  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    Default: 0-01:30:00.00     Value: 0-00:00:30.000-99-99:99:99.999

    Specifies the amount of time between checks for faulty servers.
    Applicable only to servers that have external time-providers.