Genderfluid refers to people who have different gender identities at different moments. They can identify as a man or a woman or both at the same time.
There is no determined time or length. Feeling like they belong to a gender identity depends on each person and their situation. The most common characteristic of genderfluid people is that their gender identity can fluctuate. Being genderfluid does not imply being dissatisfied with the sex assigned at birth, nor is it associated with the sexual orientation.