/sys$common/syshlp/helplib.hlb ANALYZE, /ERROR_LOG, Qualifiers, /BEFORE  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /BEFORE[=date-time]

    Specifies that only those entries dated earlier than the stated
    date and time are to be selected for the error report. If you do
    not specify a date or time, all entries are processed.