Set the coupon date range
Go to Ticketing & Payments > Coupons.
Open the coupon’s Actions menu and choose Edit Coupon.
Under Availability, enter Active From and Active To, then select Save.
Dates use the event’s timezone. The coupon is available from the start of the first day through the end of the final day. Leave either date blank to keep that end of the range open. The coupon must also be active and within its redemption limit. You can set the same dates when creating a coupon with Add Coupon.