in broad daylight ———— 光天化日（非正式）

英文释义
(INFORMAL) Clear and sufficient natural light in which everything is visible.

例句
My aunt's purse was stolen from her in broad daylight yesterday, not in some dark alley.
我姑姑的钱包是昨天在光天化日之下被人偷走的，不是什么黑暗的巷子里。