This is referred to in mission planning as Hybrid Local Solar Time (HLST). The time scales are uniform in the sense of mean solar time (they are actually mean time of some longitude), and are not adjusted as the rovers travel. (The rovers have traveled distances that make a few seconds difference to local solar time.)
Answer: An independent variable is exactly what it sounds like. It is a variable that stands alone and isn't changed by the other variables you are trying to measure. For example, someone's age might be an independent variable.
In an equation, there are two types of variables: independent and dependent. These values represent mathematical tools that are used in an experiment. Independent and dependent variables allow a researcher to maintain control, measure results, and draw accurate conclusions. The basic definition of independent and dependent variables is universal in both science and math. However, the way the variables are used differs depending on whether you are conducting a scientific experiment, performing a math problem, or studying statistics.