ISO date min max

iso-date-min-max · version 1.0.0 · Dates & times (UTC, ISO 8601) · free, no key needed

Return the earliest and latest date in a non-empty array of YYYY-MM-DD calendar dates.

Use when you need to: iso date min max · earliest and latest date · date array bounds.

Supported

• iso date min max
• earliest and latest date
• date array bounds

Not supported

• index of min
• datetime input
• timezones

Behavior

• dates is a non-empty array of strict YYYY-MM-DD proleptic Gregorian UTC calendar dates with year 0001-9999, at most 10000 items.
• min and max are the earliest and latest input dates by civil day serial.
• Ties keep the value unchanged; duplicates do not affect the result.

Input

• dates (array of string, required): min items 1; max items 10000; each min length 10; each max length 10; each pattern ^\d{4}-\d{2}-\d{2}$

Output

• min (string, required): min length 10; max length 10
• max (string, required): min length 10; max length 10

Limits

• max items: 10000
• year min: 1
• year max: 9999

Example

Request input:

{
  "dates": [
    "2026-03-01",
    "2026-01-01",
    "2026-02-01"
  ]
}

Response:

{
  "result": {
    "min": "2026-01-01",
    "max": "2026-03-01"
  }
}

How to call it

MCP

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

{
  "id": "iso-date-min-max",
  "version": "1.0.0",
  "input": {
    "dates": [
      "2026-03-01",
      "2026-01-01",
      "2026-02-01"
    ]
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/iso-date-min-max/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"dates":["2026-03-01","2026-01-01","2026-02-01"]}'

The machine-readable contract is at /v1/tools/iso-date-min-max/versions/1.0.0.

CLI

node cli.mjs run iso-date-min-max 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• ISO date clamp: Clamp a YYYY-MM-DD calendar date into an inclusive [min, max] range.
• ISO date quarter bounds: Return the calendar quarter number and the first/last dates of the quarter containing a date.
• ISO date week bounds: Return the Monday and Sunday of the ISO-8601 week that contains a calendar date.
• ISO date business day add: Add a signed count of business days to a date, skipping caller-supplied weekend weekdays and holidays.
• ISO date to week: Convert a YYYY-MM-DD calendar date to an ISO-8601 week date.
• ISO date-time clamp: Clamp a strict UTC ISO-8601 datetime into an inclusive [min, max] range.