Is staying up late for work and then sleeping through the Dhuhr prayer until the Asr prayer considered an excuse, or does it fall under heedlessness concerning prayer?

It is permissible to perform the prayer at any part of its time, and a Muslim does not incur sin by delaying it until the end of its time, as long as he performs it before its time expires. If the worshipper knows that he will pray at the end of the time, there is no sin upon him. Congregational prayer is obligatory for adult men, and it is obligatory to strive to perform it, even at home with one's family. If the worshipper sleeps before the prayer time begins, it is recommended for him to take measures to wake up, and some scholars have deemed it obligatory. However, if he wakes up after the time has begun, it is not permissible for him to go back to sleep unless he is reasonably certain that he will wake up before the time expires.