RFC 3339 Converter

Convert Local Time to RFC 3339

If you’ve ever needed to format a timestamp for an API, database, or international schedule, you’ve probably bumped into the RFC 3339 standard. This tool takes the guesswork out of converting your local date and time into the exact format many web systems rely on.

Why this converter is handy

You don’t need to be a developer to find yourself dealing with date formats. Whether you're scheduling across time zones, working with APIs, logging data, or just making sense of UTC, this calculator lets you convert a familiar date and time into an RFC 3339 timestamp—accurately and quickly.

How to use it

Step 1: Enter your local date and time

Use the date picker and time input at the top. The tool automatically fills in the current date and time, but you can edit it to whatever you need.

Step 2: Choose the timezone

Pick from the list of common time zones—including Eastern, Pacific, London, Berlin, Tokyo, and more. If you're working in UTC, just leave it on the default setting.

Step 3: Click “Convert to RFC 3339”

Once your inputs are set, hit the button in the center. The result appears in the formatted box below, ready to copy and paste into whatever you're working on.

Customize the format your way

Below the output box, you'll find two options:

• Include milliseconds: Adds the fractional second component, which some systems require.
• Use 'Z' for UTC: Outputs a “Z” suffix instead of a numeric time offset if you’re in UTC. This is common in APIs and log files.

You can toggle these on or off at any time. If you've already converted a time, changing either checkbox will refresh the output automatically.

Need to check the current time?

In the bottom panel, the live time is always visible. There's also a button to switch between 12-hour and 24-hour display formats. This doesn’t change your input—just the way the clock looks, which can help if you’re used to one style over the other.

A few tips if your time looks off

• Make sure both date and time are filled in—if one is missing, the converter won’t run and will ask you to complete it.
• Remember that timezone selection matters. If your input is 3 PM in Tokyo but you accidentally selected New York, the final result won’t be what you expect.
• Changing formatting options after conversion? No need to press the convert button again—the tool will automatically refresh the output for you.

Keep your timestamps clear and your timezones straight

Whether you're coding, scheduling, or just trying to get a time right across continents, this converter gives you what you need: a clear, standard format that’s accepted just about everywhere. It's built to save you time—and more than a few headaches.