This is in the link:
To obtain a divorce on this basis (irretrievably broken), one
party must establish that he or she refuses to live with the
other spouse and that there is no hope of reconciliation. It
is not necessary for both parties to agree the marriage is
irretrievably broken. Also, it is not necessary to show that
there was any fault or wrongdoing by either party.
To obtain a divorce on one of the 12 fault grounds, one
must prove that there was some wrongdoing by one of the
parties to the marriage.
As an example, one fault ground is adultery. Adultery in
Georgia includes heterosexual and homosexual relations
between one spouse and another individual.
Another fault ground for divorce in Georgia is desertion.
A divorce may be granted on the grounds that a person
has deserted his or her spouse willfully for at least one
year. Other fault grounds include mental or physical
abuse, marriage between persons who are too closely related
mental incapacity at the time of marriage, impotency, force or fraud in obtaining the
marriage, pregnancy of the wife unknown to the husband
at the time of the marriage, conviction and imprisonment
for certain crimes, habitual intoxication
or drug addiction
and mental illness.
So for no fault, no time is needed. For a fault, there can be desertion - one year is required.