Update, May 17 |

Can I search for my name?

Yes. It is now possible to search the “Moment in Time” interactive gallery by the name given in the photographer’s credit line (actual name, pseudonym or screen name, as the contributor chose). You’ll find the search box in the upper right corner of the opening page. If you believe your picture wasn’t posted, we urge you to give this a try.

Update, May 13 |

Where Is My Picture?

Contributors who haven’t found their pictures in the gallery (be sure you’ve looked under “All”) may resubmit to pix@nyt.com. Attach a JPEG file, no larger than 5MB, to an e-mail message with your name, location and caption. Write “Moment” in the subject line. Your picture should have been taken at 15:00 U.T.C. on Sunday, May 2. Resubmit only the image you originally sent; nothing new. We apologize and thank you for your patience.

Where Is My Credit?

Contributors whose pictures have been published without credit should send an e-mail message to lensnytimes@gmail.com with their name and the URL of their picture. (It’s a long one, beginning www.nytimes.com and ending with a string of two dozen numbers and letters.) Again, please accept our apologies.

Update, May 11 | The interactive gallery is now open.

Original post | Attention: everyone with a camera, amateur or pro. Please join us on Sunday, May 2, at 15:00 (U.T.C./G.M.T.), as thousands of photographers simultaneously record “A Moment in Time.” The idea is to create an international mosaic, an astonishingly varied gallery of images that are cemented together by the common element of time.

How do I submit my picture?

Call up this form, submit.nytimes.com/moment, which should be self explanatory. That’s all there is to it. (If you’re looking at the submission form before Sunday, May 2, or after Friday, May 7, you’ll find that you can read it but can’t actually use it. )

How long do I have to submit my picture?

Five days, until 15:00 (U.T.C.) on Friday. We recognize that not every photographer will be near a computer on Sunday. Some of you may not be able to get to a computer for days. This extended deadline is for you.

How many pictures may I send in?

One. If you’ve shot several over the space of a moment or two, send the single best.

Do I have to take my picture at exactly 15:00?

No. We don’t expect atomic-clock precision. And we’d rather you send a good picture taken one minute after the hour than a mediocre picture taken exactly on the hour.

We ask only that you come as close to 15:00 as is reasonably possible. Keep in mind that the purpose of this exercise is to create a marvelously simultaneous portrait of our world and its people.

What if I cheat?

Come on. Why would you?

Look, we trust you. Besides, there aren’t enough cups of coffee in New York to keep our tiny staff awake for the time it would take to peruse the metadata in every single JPEG we receive. So we’re relying on you to understand that any significant departure from the benchmark hour only subverts the communal enterprise.

Of course, if we’re presented with evidence that your entry wasn’t taken close to 15:00, we’ll remove it from the gallery.

How much may I alter the image?

Not much.

You may certainly crop the edges. You may also perform minor adjustments, like color balancing, that are intended to increase the photo’s verisimilitude; in other words, to make the image on your screen resemble the scene that was before your eyes as closely as possible.

But please don’t even think of cloning any element into or out of it. Don’t do anything you couldn’t have done simply and easily in a darkroom. (If you know what a darkroom is.)

What about adding or subtracting or combining elements?

Again, don’t.

Here is The Times’s news policy, which we’re applying to this project, too: “Images in our pages, in the paper or on the Web, that purport to depict reality must be genuine in every way. No people or objects may be added, rearranged, reversed, distorted or removed from a scene (except for the recognized practice of cropping to omit extraneous outer portions).”

And if I do so anyway?

Really, why would you? We’re not going to pore over submissions looking for fakery and fraud. But we will remove any photographs that are demonstrably manipulated. Please, just spare us.

Color or black and white? Horizontal or vertical or square?

Your choice.

May I use my cellphone camera?

By all means. We’re suckers for the medium. See “Reader’s Photos: Call Forwarding.”

May I shoot my picture on old-fashioned film?

Absolutely, though you’ll have to convert your negative, print or slide into a JPEG file in order to submit it. Given the five-day deadline, that ought to be possible, even going through a commercial photo-finisher. (If you know what that is.)

Who’ll own my picture?

You will. You own the picture. You own the copyright.

What you’re doing is granting a limited license to The Times to reproduce your picture. Here’s the deal in its entirety: “By submitting to The New York Times, you are promising that the content is original, doesn’t plagiarize from anyone or infringe a copyright or trademark, doesn’t violate anybody’s rights and isn’t libelous or otherwise unlawful or misleading. You are agreeing that we can use your submission on Lens, the photojournalism blog of The New York Times, and in the online and print version of the New York Times promoting or referring to the Lens post.”

Do I keep the copyright on the picture?

Yes, you do. See the answer above.

Do I have to make my full name public?

It’s certainly our preference that you do. And we think it adds a personal dimension to your submission. But, no, it’s not a requirement.

What about the caption?

Keep it concise, please. Just a sentence or two. The form will actually prevent you from writing much longer than that.

And specifying my location?

On the submission form, you’ll find a Google map that will help you pinpoint your location. If you’re not in a settled place, you might also want to note in your caption that the picture was taken on the Zambezi River, atop Mount Agamenticus, or the like.

Anything else I need to know?

The submission form will ask you to choose a topic under which you think your photo best fits. They are: arts and entertainment, community, family, money and the economy, nature and the environment, play, religion, social issues and work. You can also select “other.”

When will I start seeing results on the Web?

By Sunday evening, we hope to have posted a small sampler of images; not really the “best of,” but a brief overview of the many places and people and situations our contributors managed to capture. Early in the following week, we plan to post a much fuller gallery, with thousands of images. Frankly, the timing depends somewhat on the number of submissions we receive and how much editing is needed. There’ll be no way to know for certain until it actually happens.

How can I find out if you’ve used my picture?

Our plan — emphasis, “plan” — is to post almost every picture we receive. So your work will almost certainly be included, unless it fails any of the tests mentioned above or is more graphic than news photographs we would customarily publish.

The interactive gallery that will appear next week takes the form of a globe on which you can find your location, or those of other photographers. It was designed by Zach Wise of The Times and is, to use highly technical professional vernacular, too cool for school.

Will I get paid?

Not by us. But the photo is yours, after all. Make of it, or out of it, what you will.

What is Coordinated Universal Time (U.T.C.) anyhow?

It’s an accepted worldwide benchmark against which all local time zones can be expressed, plus or minus. Informally speaking, it’s the equivalent of what you may know as Greenwich Mean Time (G.M.T.).

Here’s a helpful converter.

Eastern Daylight Time is four hours behind U.T.C., meaning that it will be 11 a.m. in New York. Central Daylight Time is five hours behind, so it will be 10 a.m. in Chicago. Mountain Daylight Time is six hours behind, so it will be 9 a.m. in Denver. And Pacific Daylight Time is seven hours behind. (Good morning, San Francisco!)

It will be noon in Buenos Aires, 4 p.m. in London, 5 p.m. in Cape Town, 6 p.m. in Baghdad, 7 p.m. in Moscow, 8:30 p.m. in Mumbai (yes, there’s a half-hour difference), 10 p.m. in Bangkok, 11 p.m. in Beijing, midnight in Tokyo and 1 a.m. Monday in Sydney.

Why is Coordinated Universal Time abbreviated U.T.C.?

Don’t ask.