D-Link DFL-600 - Manual (Page 59)

A schedule called NoWeekDays has been entered with the hours between 6
pm and 9 pm checked for the weekdays Monday through Friday. Click on
the Apply button to enter this schedule into the Schedule Table.
You can enter up to 15 Schedules, but two default schedules are
automatically maintained by the DFL-600
− Always and None. You can
make changes to the None Schedule, but the Always Schedule is intended for
policies that should always be enforced.
To check the entered schedules, click the Schedule Table link. This will
open the Schedule Table, as shown below.