A weekly roster, late and early worked out for you, and leave requests.
Staff, Attendance, Roster: set each person's shifts for the week.
Staff clock in at the desk QR: open Staff, Attendance, Clock-in screen on a tablet at the desk (or they use their location). Late and early are worked out from the roster.
Leave: staff ask in My work; a manager approves. Set the yearly quota in Staff, a person, Leave, Leave policy.