#compdef date

_arguments \
    '-d[date]:time string:' \
    '-f[file]:date file:_files' \
    '-I[iso-8601]:time spec:' \
    '-r[reference]:file:_files' \
    '-R[rfc-2822]' \
    '-s[set]:time string:' \
    '-u[utc]' \
    -- \
    '*=FILE*:file:_files' \
    '*=DATEFILE*:date file:_files' \
    ':format or date:'