Available start time, optional, accurate to the minute.
It is recommended to set it to a future time.
When both the start time and end time are left blank, there is no restriction on the product’s sale period.
When only the start time is set, the product cannot be sold before the start time.
It can be sold from the start time onward, with no end time for the sale.
When both the start time and end time are set, and the start time is earlier than the end time, the product can be sold from the start time onward; it cannot be sold once the end time is reached.
If the end time is earlier than or equal to the start time, the setting will become invalid.
The product may not be added to the shopping cart, or checkout may fail.
If only the end time is set, the setting will also become invalid and may prevent customers from completing checkout.
銷售開始時間，選填，精確至分鐘。
建議設定為未來時間。
開始時間與結束時間皆留空時，表示不限制商品的銷售時間。
僅設定開始時間時，商品在開始時間前不可售；自開始時間起可售，且沒有銷售結束時間。
若同時設定開始時間與結束時間，且開始時間早於結束時間時，商品自開始時間起可售；結束時間到達後即不可售。
若結束時間早於或等於開始時間，則屬於無效資料，商品可能無法加入購物車或完成結帳。
若僅設定結束時間，也屬於無效資料，可能導致顧客無法完成結帳。
