Final answer:
The time when students can change their class schedules without penalty is known as the add/drop period, occurring at the start of a semester.
Step-by-step explanation:
The period of time that a student can make changes to his/her schedule without penalty is commonly referred to as the 'add/drop period' or the 'registration change period.' During this time, students have the flexibility to adjust their class schedules by adding or dropping courses. This period usually occurs at the beginning of the semester and is designed to provide students with the opportunity to finalize their schedules after having attended the first few classes or upon further consideration of their academic plan. It is important for students to be aware of this period and make any desired changes to their schedule within this timeframe to avoid penalties such as fees or academic consequences such as a 'W' for withdrawal on their transcript, which can affect their grade point average.