Duration convert

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

Convert a canonical integer duration between nanosecond-based SI units as an exact rational.

Use when you need to: duration convert · convert duration units · convert seconds minutes hours days.

Decide before calling

Read the versioned contract and the supported scope below. Reuse duration-convert@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-convert@1.0.0 for duration convert. 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

• duration convert
• convert duration units
• convert seconds minutes hours days

Not supported

• months
• years
• weeks
• leap seconds
• ISO-8601 duration strings
• floats
• calendar dates

Behavior

• value is a canonical integer string amount in the from unit; -0 is accepted and canonicalized to 0.
• Units are ns, us, ms, s, min, h, and day from DURATION_NS; day is exactly 86400 seconds.
• Conversion is the exact rational value * from_ns / to_ns, reduced with sign only on the numerator.
• Negative durations are allowed; leap seconds, months, years, and ISO-8601 duration strings are rejected.
• Input integers and the reduced numerator and denominator may have at most 1000 digits excluding sign.

Input

• value (string, required): max length 1001; pattern ^-?(0|[1-9][0-9]*)$
• from (one of "ns", "us", "ms", "s", "min", "h", "day", required)
• to (one of "ns", "us", "ms", "s", "min", "h", "day", required)

Output

• numerator (string, required): pattern ^(0|-?[1-9][0-9]*)$
• denominator (string, required): pattern ^[1-9][0-9]*$

Limits

• max digits: 1000
• units: ["ns","us","ms","s","min","h","day"]

Example

Request input:

{
  "value": "90",
  "from": "s",
  "to": "min"
}

Response:

{
  "result": {
    "numerator": "3",
    "denominator": "2"
  }
}

How to call it

MCP

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

{
  "id": "duration-convert",
  "version": "1.0.0",
  "input": {
    "value": "90",
    "from": "s",
    "to": "min"
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/duration-convert/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"value":"90","from":"s","to":"min"}'

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

CLI

node cli.mjs run duration-convert 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.
• Duration format clock: Format a nonnegative whole or decimal second count as an exact hh:mm:ss[.fraction] clock duration.
• Working hours total: Total exact elapsed seconds in a versioned working-hours calendar after DST and closure expansion.
• Duration add: Sum mixed SI duration terms in nanoseconds and return the exact rational in a target unit.
• ISO to epoch: Convert a canonical RFC 3339 UTC timestamp to an exact integer Unix epoch count in the requested unit.