To be honest, if people are not told they need to give advanced notice for using their time off they often won't - especially when nobody else does. Obviously,

To be honest, if people are not told they need to give advanced notice for using their time off they often won't - especially when nobody else does. Obviously, it's not always possible to give advanced notice (illness or other unforseen circumstances), so most employers require a brief explanation when advanced notice isn't possible - "Sick kid," "car trouble," "illness," etc. These are normal policies, but they must be formal policies and communicated to employees. If those policies are in place and you have people violating them - then it becomes an HR issue, with formal reprimanded, so a low level manager shouldn't have to complain about it.