Is it permissible to delay the ritual bath (ghusl) after menstruation until after Maghrib (sunset), knowing that menstruation stops after Dhuhr (noon), due to a practical workshop session that lasts from morning until night and cannot be missed?

The cessation of menstruation must be observed at prayer times and before sleep, and one should hasten to perform ghusl immediately upon confirming its cessation. It is not permissible to delay ghusl until the time for the obligatory prayer has expired. If menstruation ceases and a woman is unable to perform ghusl due to harm or the unavailability of a place, she should perform tayammum and pray, then perform ghusl whenever she is able to use water.