When you feel comfortable with the title of atheist. I was comfortable with title immediatly after I accepted there is no god and religion is for fools, 6 1/2 months ago.

I don't worry much about labels, but if you want to be accurate about what you believe and don't want to make a long explanation when asked, choose the word that best describes what you think about how you feel. don't choose the label first. find out how you feel first.

g

All true religious beliefs have to be explored and defined from being 'Atheistic' from the ground floor. So being now in the existential realm you must examine all religious and historical evidence available which will take you into the realms of Philosophy and many reading of ancient authors of renown.
Agnosticism is full blown healthy skepticism that exists in ever religious persons cognitive mind because all documented religions are based upon belief and lack the historical and documented findings or record.
We are not mentioning another Scientific Source of Creation which is becoming more evident as we explore the stars and planets which go way back into history.

I made the decision to be atheist when I was talking to an ex-boyfriend. Explaining that I could entertain the concept of god, but that I really didn’t care and didn’t see any evidence for it. If someone pressed me for a yes or no answer I would say no god.

He made the observation that a lot of people aren’t atheist because of the stigma attached to the word atheist. I thought that was a good point and decided that I was atheist.

If you want to signal to others that you're open to conversion, tell them you're an agnostic.

If you feel you've given deities the same chance you gave Santa Clause and you'd rather talk about other things, tell them you're an atheist.

It's simple

Do you believe God has a possibility to exist? Do you believe there absolutely is no god?

If the former agnostic, the latter atheist

Or maybe 'Hitchen's Razor' might help you in your decision...

"What can be asserted without evidence can be dismissed without evidence"

When the question is no longer relevant

@Rhetoric -- When one looks at the meaning of the two words it becomes apparent that they may both be used simultaneously. I am an atheist because I don't hold any belief in any deities and by extension in nothing else related to the supernatural. However, when discussing the issue I am agnostic. I cannot make the claim that there is no god because of the supporting evidence issue. If I make that claim, the burden of proof rests with me, and that is a fool's folly. So, the fact that I don't believe in the supernatural/god(s)/fairies/pixies and other nonsense does not automatically make me right. I can provide a rational and logical argument, but I can't provide adequate evidence to prove my stance.

I suggest to you that the time is now, if you do not believe. Call yourself atheist, but do not make absolute statements about the non existence of god or gods. It really is simple. "I don't believe in god," is different from, "There is no god." One is a condition, while the other is an activity.