Calendar Generator

How to use Calendar Generator

Create a Monday-first monthly calendar with ISO dates and download its day-by-day data. This calendar generator works directly in your browser and is free to use without an account.

1. Paste or open your input in the editor.
2. Run the tool and inspect the output. If the input is invalid, correct the reported error and run it again.
3. Copy the result or download it to your device.

Calendar Generator · Example

2026-09-01

{
  "year": 2026,
  "month": 9,
  "firstWeekday": 2,
  "days": [
    {
      "date": "2026-09-01",
      "day": 1,
      "weekday": 2
    },
    {
      "date": "2026-09-02",
      "day": 2,
      "weekday": 3
    },
    {
      "date": "2026-09-03",
      "day": 3,
      "weekday": 4
    },
    {
      "date": "2026-09-04",
      "day": 4,
      "weekday": 5
    },
    {
      "date": "2026-09-05",
      "day": 5,
      "weekday": 6
    },
    {
      "date": "2026-09-06",
      "day": 6,
      "weekday": 7
    },
    {
      "date": "2026-09-07",
      "day": 7,
      "weekday": 1
    },
    {
      "date": "2026-09-08",
      "day": 8,
      "weekday": 2
    },
    {
      "date": "2026-09-09",
      "day": 9,
      "weekday": 3
    },
    {
      "date": "2026-09-10",
      "day": 10,
      "weekday": 4
    },
    {
      "date": "2026-09-11",
      "day": 11,
      "weekday": 5
    },
    {
      "date": "2026-09-12",
      "day": 12,
      "weekday": 6
    },
    {
      "date": "2026-09-13",
      "day": 13,
      "weekday": 7
    },
    {
      "date": "2026-09-14",
      "day": 14,
      "weekday": 1
    },
    {
      "date": "2026-09-15",
      "day": 15,
      "weekday"
…

Create a Monday-first monthly calendar with ISO dates and download its day-by-day data. Long examples are shown as excerpts.

Usage notes

Inputs and results are processed on this device. Tool content is not sent to a processing server.