This option allows you to customize the specific date(s) at which the campaigns appear. For example, if there is a discount code that only lasts for 5 days, a campaign with the discount code could be set to appear only for May 20th to May 25th. Or, you could simply chose to keep the campaign on year-round.
Time of Day
Similar to Date Range, however you are able to set the time of day of which the campaign appears, or, you could keep the campaign on all day.