In the Campaign Details Report, which you can access here, you get an overview of the configuration options selected by the campaign initiator, as well as the current status of the campaign.
Start Date:
This is the date and time the campaign is valid from. In the case where a voucher code is included in the campaign, this is also the date/time from which voucher redemptions will be permitted.
End Date:
This is the date and time the campaign will conclude. In the case where a voucher code is included in the campaign, this is also the date/time from which voucher redemptions will no longer be permitted.