Full-time means that you are dressing and living in your preferred gender role all the time.
I was part-time from the time I came out to my wife until I came out to my neighbours. I dressed femme at home and for visits to my therapist or support group, but dressed in male disguise at other times. I went full time a month and a half ago, after being on HRT for three months. I got rid of all my male clothes. Now, I only present as Kathy. I use no other name in spite of what my official identification says, regardless of where I am.
