Your hands swirl with dreamlike sand and dust that sprays out in a 60-foot cone. Roll 10d8. Each creature in the area with hit points equal to or less than your total must make a Charisma saving throw. On a failed saving throw, a creature falls asleep and unconscious until the spell ends, the creature takes damage, or someone uses an action to shake or slap the creature awake. On a success, a creature becomes immune to this casting of sandman's slumber.

Until the spell ends, you can use an action on each of your turns to release another cloud of dust, with the same effects as when the spell is initially cast.

If you maintain your concentration on this spell for the entire possible duration, any creatures that are still sleeping do not wake up. Each creature remains asleep until it finishes a long rest, takes damage, or someone uses an action to wake the creature.

Undead, contructs, and creatures that can't be charmed are immune to the spell.