Do the per-minute rates on phone cards change depending on the time of day used?
In most cases, no. Most cards have the same rates 24 hours per day, 7 days per week, including holidays. However, there are some cards that may have different rates during peak periods, e.g., Monday through Friday from 8 AM through 5 PM. The rate chart for the phone card should list the applicable rates. Note that rates are always subject to change without notice.
