Your question does not make sense. The title of the question, however, gives an idea about what you want to know. May I request you to be more specific in your question so that the answer can be equally so?
The correct term is '30 days' sight'. It means that the amount will be due for payment (or 'mature' for payment) 30 days from the day the usance draft is accepted by the drawee.
This definition applies to both bills drawn under LC (usance or acceptance LCs) and also non-LC DA bills.