3Com 8807 Command Reference Manual page 233

If a time range only defines the absolute time range, the time range is only active
within the absolute time range.
If a time range only defines the absolute time range and multiple ranges of this
time range are available (repeating this time range name can configure multiple
absolute time ranges of the same name), the time range is active only within these
absolute time ranges.
If a time range defines the period time range and the absolute time range, the
time range is only active when the period time range and the absolute time range
are both matched. For example, a time range defines a period time range which is
from 12:00 to 14:00 every Wednesday, and defines an absolute time range which
is from 00:00 2004/1/1 to 23:59 2004/12/31. This time range is only active from
12:00 to 14:00 every Wednesday in 2004.
If a time range defines multiple absolute time ranges and multiple period time
ranges, the time range is active only when period time ranges and absolute time
ranges are both matched, that is, take the union set of multiple absolute time
ranges and multiple period time ranges, and then take the intersection set of the
union set of multiple absolute time ranges and that of multiple period time
ranges.
If the start time and end time are not configured, the time range is one day
(00:00-24:00).
If the end time is not configured, the time range is from the day when the
configuration takes effect to the biggest time supported by the system. The
maximum time range supported by the system currently is from 1970/01/01 to
2100/12/31.
n
If you include any argument in the undo time-range command, the system
■
will delete only the content defined by the argument from the time range.
When you configure a time range, avoid naming the time range with "a",
■
"al", or "all" to prevent collision with the all key word.
If you input parameters in the undo time-range command, only the content
corresponding to the specified time range will be canceled.
Example
# Define a time range starting from 0:0, Jan. 1, 2000.
<SW8800> system-view
System View: return to User View with Ctrl+Z.
[SW8800] time-range test from 00:00 2000/1/1
ACL Commands 231