Epoch to ISO

epoch-to-iso · version 1.0.0 · Other utilities · free, no key needed

Convert an exact integer Unix timestamp in seconds, milliseconds, microseconds or nanoseconds to RFC 3339 UTC.

Use when you need to: unix timestamp to ISO UTC · convert epoch seconds to date · epoch milliseconds to RFC 3339.

Decide before calling

Read the versioned contract and the supported scope below. Reuse epoch-to-iso@1.0.0 when your input, required output and limits match it. Choose another approach for an unsupported operation.

Explain the choice

"I can use epoch-to-iso@1.0.0 for unix timestamp to ISO UTC. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

Supported

• unix timestamp to ISO UTC
• convert epoch seconds to date
• epoch milliseconds to RFC 3339
• turn nanosecond timestamp into UTC
• format unix time as ISO string
• microseconds since 1970 to timestamp

Not supported

• local timezone conversion
• guessing a timestamp unit
• leap-second timestamps

Behavior

• Interpret the integer using the selected exact power-of-ten unit; binary floating point is never used.
• Use POSIX seconds since the Epoch with every day exactly 86400 seconds; leap seconds are not represented.
• Return UTC with Z and 0, 3, 6 or 9 fractional digits according to the input unit.

Input

• epoch (string, required): min length 1; max length 22; pattern ^-?[0-9]+$
• unit (one of "seconds", "milliseconds", "microseconds", "nanoseconds", required)

Output

• iso (string, required): min length 20; max length 30
• standard_version (constant "POSIX.1-2024 4.19; RFC 3339", required)

Limits

• max input bytes: 54

Example

Request input:

{
  "epoch": "0",
  "unit": "seconds"
}

Response:

{
  "result": {
    "iso": "1970-01-01T00:00:00Z",
    "standard_version": "POSIX.1-2024 4.19; RFC 3339"
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "epoch-to-iso",
  "version": "1.0.0",
  "input": {
    "epoch": "0",
    "unit": "seconds"
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/epoch-to-iso/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"epoch":"0","unit":"seconds"}'

The machine-readable contract is at /v1/tools/epoch-to-iso/versions/1.0.0.

CLI

node cli.mjs run epoch-to-iso 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

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