Not sure I understand the question. "Full time" often refers to hours worked at of job. A full time job in the U.S. means that you work the normal work week for that job. Usually 37.5 to 40 hours a week. A part-time job is anything less than that but because of regulatory reasons is usually less than 32 hours a week and often significantly less.
"which the time available I can use" has no meaning for me. Perhaps "How much time can I work?" or "How much time am I available to work?".