What is the specific time for children not to go out an hour or half an hour before Maghrib?

The specific time to keep children indoors is at sunset or shortly before it, and the prohibition lasts until the intensity of the darkness between Maghrib and Isha subsides, as the Prophet, peace and blessings be upon him, said: "When night falls—or when you enter upon evening—keep your children in, for the devils spread out at that time. But when an hour of the night has passed, you can let them go." And also his saying: "Do not send out your livestock and your children when the sun sets until the blackness of the 'Isha' (night) has gone, for the devils are let loose when the sun sets until the blackness of the 'Isha' has gone." These commands are considered by most scholars to be recommendations and guidance.