Days between dates

Calculate the number of whole days between two calendar dates. The difference uses millisecond timestamps divided by 24 hours, floored to an integer day count.

When to use it

• Project timelines and sprint lengths
• Rental or subscription period checks
• Teaching date arithmetic without spreadsheets

Limitations

Does not count business days or exclude holidays. End date must be on or after the start date. Invalid date strings return zero without a network lookup.

Example

From 2024-01-01 to 2024-01-11 yields 10 whole days—the end date is not counted as an extra calendar day in this calculator. From 2024-02-28 to 2024-03-01 in a leap year yields 2 days, while the same pair in a non-leap year still spans two midnights. Same-day start and end return 0, which is useful when validating that a rental period has not yet begun.

This skill is available over A2A JSON-RPC and REST. When you already know the skill id and export, call execute directly—no discovery step required.

REST example

curl -sS -X POST https://toolplaza.app/api/helpers/execute \
  -H 'Content-Type: application/json' \
  -d '{"skillId":"date__days-between","export":"daysBetweenDates","args":["Hello"]}'

A2A JSON-RPC example

Send POST https://toolplaza.app/api/a2a with:

{
  "jsonrpc": "2.0",
  "id": "1",
  "method": "message/send",
  "params": {
    "message": {
      "messageId": "uuid",
      "role": "user",
      "parts": [
        {
          "kind": "text",
          "text": "ignored"
        }
      ]
    },
    "metadata": {
      "toolplaza": {
        "skillId": "date__days-between",
        "export": "daysBetweenDates",
        "args": [
          "Hello"
        ]
      }
    }
  }
}

Full Agent API guide · Skill schema