Questions & Answers about hajiman oneureun jumarira yeyageul chwiso mos haeyo.
Here -이라 is a contraction of -이어서 or -이니까, meaning “because it’s the weekend.” It links the noun 주말 to the reason clause. Alternatives include:
• 주말이어서 예약을 취소 못 해요.
• 주말이니까 예약을 취소 못 해요.
All three convey the same “since it’s the weekend.”