Bell of Alarm

This brass bell doesn't have a clapper inside it and has 4 charges. As an action, you can expend 1 of the bell's charges to shake it and speak its command word, followed by a total number of hours, minutes, or seconds equal to no more than 8 hours. After the specified amount of time has passed, the bell emits a loud ringing in your ears that's audible to only you, provided that you're within 1 mile of the bell and are on the same plane of existence. You can mentally end a timer at any time using a bonus action. The bell regains all expended charges daily at dawn.