oil light

JUst recently a light has come on inside my daughter's 2002 Saturn that says "change oil". The oil was changed a month or so ago. Any comments or advice???
Many thanks, Lansdowne

These cars use an algorithm to determine when to turn that light on. This algorithm takes into account many operating conditions of the car to figure out the condition of the oil. When the oil is changed this oil life indicator needs to be reset; different cars use different methods to reset this indicator, look for it in your owner's manual, most Saturns use a button in the underhood fuse panel.