Working Days Grounding Data

Overview

Pass a two-letter country code and a month number. The API returns totals for working and non-working days plus a list of working dates formatted as YYYY-MM-DD. Each non-working day specifies reasons such as weekends or public holidays, with holiday names included when applicable. Paid plans can set a custom year.

Live Test Working Days Grounding Data Source →

The tool

Once your client is connected to the VerveContext server, this appears in its tool list as WorkingDaysGroundingData. 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.

{
  "name": "WorkingDaysGroundingData",
  "arguments": {
    "country": "US"
  }
}

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

Connecting

One server URL covers every source 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": {
    "vervecontext": {
      "url": "https://api.vervecontext.com/v1/mcp"
    }
  }
}

https://api.vervecontext.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.

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.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103

{
  "status": "ok",
  "error": null,
  "data": {
    "workingDaysCount": 21,
    "nonWorkingDaysCount": 10,
    "workingDays": [
      "2023-10-02",
      "2023-10-03",
      "2023-10-04",
      "2023-10-05",
      "2023-10-06",
      "2023-10-10",
      "2023-10-11",
      "2023-10-12",
      "2023-10-13",
      "2023-10-16",
      "2023-10-17",
      "2023-10-18",
      "2023-10-19",
      "2023-10-20",
      "2023-10-23",
      "2023-10-24",
      "2023-10-25",
      "2023-10-26",
      "2023-10-27",
      "2023-10-30",
      "2023-10-31"
    ],
    "nonWorkingDays": [
      {
        "date": "2023-10-01",
        "reasons": [
          "weekend"
        ],
        "holiday_name": null
      },
      {
        "date": "2023-10-07",
        "reasons": [
          "weekend"
        ],
        "holiday_name": null
      },
      {
        "date": "2023-10-08",
        "reasons": [
          "weekend"
        ],
        "holiday_name": null
      },
      {
        "date": "2023-10-09",
        "reasons": [
          "public holiday"
        ],
        "holiday_name": "Columbus Day"
      },
      {
        "date": "2023-10-14",
        "reasons": [
          "weekend"
        ],
        "holiday_name": null
      },
      {
        "date": "2023-10-15",
        "reasons": [
          "weekend"
        ],
        "holiday_name": null
      },
      {
        "date": "2023-10-21",
        "reasons": [
          "weekend"
        ],
        "holiday_name": null
      },
      {
        "date": "2023-10-22",
        "reasons": [
          "weekend"
        ],
        "holiday_name": null
      },
      {
        "date": "2023-10-28",
        "reasons": [
          "weekend"
        ],
        "holiday_name": null
      },
      {
        "date": "2023-10-29",
        "reasons": [
          "weekend"
        ],
        "holiday_name": null
      }
    ]
  }
}

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.

Why ground on it

A model can produce something that looks like this answer from its training data, and be confidently out of date or simply wrong. This source returns the current value in a shape you can check, which is the difference between an answer you can cite and one you have to hedge.

Point an evaluation at workingDaysCount: it is the field most worth pinning a claim to, and it is either present and current or absent — never plausibly invented.

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.

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

Monthly Payroll Proration

Payroll engines prorate mid-month employee salaries by dividing base pay by the exact working day count for that territory.

Project Deadline Forecasting

To forecast delivery deadlines accurately, task management software skips weekends and recognized national holidays across regional teams.

Retainer Invoice Calculations

When billing client retainer hours monthly, invoicing software checks total available business days to adjust expected service levels.

Leave Balance Deductions

Determine how many days to deduct from employee leave balances by matching vacation requests against official non-working dates.

Other ways to use Working Days Grounding Data

Set up Working Days Grounding Data on VerveContext, or reach the same source a different way. Your VerveContext account and credits work on all of them — one key, one balance.

Related

More in Calendar: