Duration format clock

duration-format-clock · version 1.0.0 · Dates & times (UTC, ISO 8601) · free, no key needed

Format a nonnegative whole or decimal second count as an exact hh:mm:ss[.fraction] clock duration.

Use when you need to: seconds to hours minutes seconds · format duration as hh:mm:ss · turn decimal seconds into clock time.

Decide before calling

Read the versioned contract and the supported scope below. Reuse duration-format-clock@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 duration-format-clock@1.0.0 for seconds to hours minutes seconds. 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

• seconds to hours minutes seconds
• format duration as hh:mm:ss
• turn decimal seconds into clock time
• display elapsed seconds as a clock
• seconds to time string
• format precise duration

Not supported

• calendar dates
• negative durations
• rounding fractional seconds

Behavior

• Accept nonnegative canonical decimal seconds with at most nine fractional digits.
• Hours may exceed 23 and are padded to at least two digits; minutes and seconds are always two digits.
• Preserve the supplied fractional digits exactly; do not round or use binary floating point.

Input

• seconds (string, required): min length 1; max length 20; pattern ^(0|[1-9][0-9]{0,9})(\.[0-9]{1,9})?$

Output

• clock (string, required): min length 8; max length 22
• standard_version (constant "packet-r90-clock-1.0.0", required)

Limits

• max input bytes: 34

Example

Request input:

{
  "seconds": "3661.250"
}

Response:

{
  "result": {
    "clock": "01:01:01.250",
    "standard_version": "packet-r90-clock-1.0.0"
  }
}

How to call it

MCP

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

{
  "id": "duration-format-clock",
  "version": "1.0.0",
  "input": {
    "seconds": "3661.250"
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/duration-format-clock/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"seconds":"3661.250"}'

The machine-readable contract is at /v1/tools/duration-format-clock/versions/1.0.0.

CLI

node cli.mjs run duration-format-clock 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• Duration parse clock: Parse an hh:mm:ss[.fraction] duration and return the exact nonnegative whole or decimal second count.
• ISO duration structure check: Check a claimed reading of an ISO 8601 duration: well-formedness, components and month/day/time totals.
• ISO to epoch: Convert a canonical RFC 3339 UTC timestamp to an exact integer Unix epoch count in the requested unit.
• Working hours total: Total exact elapsed seconds in a versioned working-hours calendar after DST and closure expansion.
• Duration application check: Check a claimed timestamp from adding or subtracting an ISO 8601 duration under explicit offset and month-end rules.
• Duration convert: Convert a canonical integer duration between nanosecond-based SI units as an exact rational.