Cream Cheese can safely be left out at room temperature for up to 2 hours.
After 2 hours at room temperature the cream cheese can start growing bacteria which could make you sick and it can begin to spoil.
So make sure to refrigerate any leftover cream cheese or any other cream cheese within 2 hours or throw it out as it could make you sick.
If the cream cheese has any mold on it, has a bad smell to it, or has become really crumbly or hard then it's bad and should be thrown out.
Cream cheese once opened will usually last for up to a week in the refrigerator.
If you want to extend the life of the cream cheese you can freeze it for use later.
However when cream cheese is frozen it loses it's texture and can also become crumbly but it's best for baked goods where the taste, texture etc won't be noticed.