Is praying late haram?

Consequences of Delaying Prayer

Neglecting the designated time for prayer is considered a serious sin, unless there is a valid reason, such as unintentional sleep or forgetfulness. According to Al-Mawsu`ah Al-Fiqhiyyah, 10/8: "Scholars have reached a consensus that it is impermissible to postpone prayer until its time has passed, unless there is a legitimate excuse."