Date Difference Skill

Overview

Date Calculator works by analyzing the dates provided and calculating the date difference. It uses advanced algorithms to calculate the date difference based on the dates and returns the calculated date difference.

Live Test Date Difference Skill Skill →

The tool

Once your client is connected to the VerveKit server, this appears in its tool list as DateDifferenceSkill. It is read-only and open-world — it fetches and never mutates anything on your side — so most clients call it without asking you to confirm.

Tool call

{
  "name": "DateDifferenceSkill",
  "arguments": {
    "start": "2022-01-01",
    "end": "2024-08-31"
  }
}

You do not name the tool yourself; the model picks it. Asking about 2022-01-01 in the terms this skill covers is enough for it to reach for DateDifferenceSkill on its own — naming it explicitly also works, and is the way to force the call.

Connecting

One server URL covers every skill in the catalog, including this one. Authorization is OAuth: the client opens a browser once, and there is no key to paste into a config file.

{
  "mcpServers": {
    "vervekit": {
      "url": "https://api.vervekit.com/v1/mcp"
    }
  }
}

Per-client setup — Claude, Cursor, VS Code, ChatGPT — is on the MCP setup page.

Arguments

These are the properties on the tool's inputSchema, so a well-behaved client validates them before the call is made. Premium arguments are accepted on every plan but only take effect on plans that include them.

Argument	Type	Description
`start`Required	string	The start date for calculating the difference (format: YYYY-MM-DD) date
`end`Required	string	The end date for calculating the difference (format: YYYY-MM-DD) date

What the model gets back

The result carries a structuredContent object matching the tool's declared outputSchema, so a client reads fields without parsing prose. status is "ok" and error is null on success; a null field means the value was not available for that input, not that the call failed.

Result

{
  "status": "ok",
  "error": null,
  "data": {
    "minutes": 524160,
    "hours": 8736,
    "days": 364,
    "weeks": 52,
    "months": 11,
    "years": 0,
    "start": {
      "date": "2022-01-01",
      "day": "Saturday",
      "month": "January",
      "year": "2022",
      "words": "Saturday, January 1st 2022"
    },
    "end": {
      "date": "2022-12-31",
      "day": "Saturday",
      "month": "December",
      "year": "2022",
      "words": "Saturday, December 31st 2022"
    }
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`minutes`	number	`524160`	Total number of minutes between start and end dates
`hours`	number	`8736`	Total number of hours between start and end dates
`days`	number	`364`	Total number of days between start and end dates
`weeks`	number	`52`	Total number of weeks between start and end dates
`months`	number	`11`	Total number of months between start and end dates
`years`	number	`0`	Total number of years between start and end dates
`start`	object	`{…}`	The start date, broken into its formatted parts
`start.date`	string	`2022-01-01`	Formatted start date in YYYY-MM-DD format
`start.day`Premium	string	`Saturday`	Day of week name for the start date
`start.month`Premium	string	`January`	Month name for the start date
`start.year`	string	`2022`	Year for the start date
`start.words`Premium	string	`Saturday, January 1st 2022`	Human-readable formatted start date with day and month
`end`	object	`{…}`	The end date, broken into its formatted parts
`end.date`	string	`2022-12-31`	Formatted end date in YYYY-MM-DD format
`end.day`Premium	string	`Saturday`	Day of week name for the end date
`end.month`Premium	string	`December`	Month name for the end date
`end.year`	string	`2022`	Year for the end date
`end.words`Premium	string	`Saturday, December 31st 2022`	Human-readable formatted end date with day and month

Failure modes

Errors come back as tool errors carrying a sentence the model can act on, not a bare status code. Error handling covers the full list.

Status	What it means
`400` / `422`	The arguments did not validate. The message names the offending one.
`401`	The OAuth session is invalid or expired — reconnect the server.
`403`	Blocked by a key restriction or an IP allow-list. Never a bad identity.
`404`	This skill is not part of VerveKit. Check the catalog.
`429`	Out of credits, or a brief rate limit. The message tells them apart.

A call costs 2 credits each time the tool actually runs; a model that reasons about the tool without calling it costs nothing.

Use cases

Billing Cycle Tracking: Subscription management platforms calculate elapsed days and months between customer signup dates and renewal periods to generate accurate prorated invoices.
Milestone Deadline Tracking: When managing sprint deadlines, engineering tools track remaining weeks and days against delivery targets to flag overdue milestones.
Hotel Stay Calculation: Booking engines compute total nights and days between check-in and check-out dates to present stay lengths and determine nightly rate totals.
Insurance Policy Eligibility: To determine policy eligibility, insurance portals calculate the total years and months between an incident date and policy inception.

Other ways to use Date Difference Skill

Set up Date Difference Skill on VerveKit, or reach the same source a different way. Your VerveKit account and credits work on all of them — one key, one balance.

Call it as a REST APIOne HTTPS endpoint and an x-api-key header, with SDKs for Node, Python and .NET.APIVerve →Reference →

Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.VerveSheets →Reference →

Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.VerveContext →Reference →